REILLY v ACCIDENT COMPENSATION CORPORATION [2022] NZHC 1008

REILLY v ACCIDENT COMPENSATION CORPORATION [2022] NZHC 1008 [12 May 2022]IN THE HIGH COURT OF NEW ZEALANDWELLINGTON REGISTRYI TE KŌTI MATUA O AOTEAROATE WHANGANUI-A-TARA ROHECIV-2021-485-000579[2022] NZHC 1008BETWEEN ALEXANDER REILLYAppellantAND ACCIDENT COMPENSATIONCORPORATIONRespondentHearing: 7 April 2022Appearances: J P Miller for AppellantJ P Coates and R E Mould for RespondentJudgment: 12 May 2022JUDGMENT OF GRICE JRe appealContentsIntroduction [1]Background [8]Treatment Injury [17]Case law — causation [19]Legal principles on appeal [24]The appellant's case [25]The test for causation [30]The District Court decision — what did the Judge do? [50]The medical evidence [98]Conclusion [106]Introduction[1] This is an appeal against a judgment of the District Court (the District Courtdecision) which dismissed an appeal against the decision of a Statutory Reviewer.1[2] The effect of the District Court decision was to uphold the original decisionmade by the Accident Compensation Corporation (the Corporation) declining cover toMr Reilly (the appellant) for a claimed treatment injury.[3] Leave to appeal was given by the District Court to appeal to the High Courtagainst the District Court decision.2[4] The treatment injury, the subject of the appeal, was a delay in providingmedical treatment. As a result of that delay, Mr Reilly became unwell withGuillain Barre Syndrome (GBS) while holidaying in the Nelson area in January 2017.He was then aged 15 years. The delay was accepted as being seven-and-a-half toeight hours in getting Mr Reilly to Nelson Hospital to start treatment for the syndrome.The delay was due to incorrect medical advice given through an out-of-hours medicalcentre helpline that Mr Reilly's mother had contacted for assistance.[5] Once Mr Reilly was taken to hospital, he was quickly diagnosed with GBS andtreatment followed. However, Mr Reilly was seriously unwell, spending some threemonths in the Intensive Care Unit at Christchurch Hospital and subsequently beingtransferred for treatment to a specialist unit at Burwood Hospital in Christchurch.Mr Reilly continues to suffer severe effects from the syndrome, including tetraplegia.According to one medical specialist who has reviewed Mr Reilly's case, any predictedfinal outcome of Mr Reilly's illness "must be guarded."3 The specialist is of the viewMr Reilly "may show more improvement in the next two or three years, although therecould be some residual disability."4 While the delay in treatment has been acceptedby it as being a treatment injury, ACC has declined the claim on the basis that it was1 Reilly v Accident Compensation Corporation [2020] NZACC 158 [District Court decision]; andReilly v Accident Compensation Corporation [2021] NZACC 140 [Statutory Reviewer'sdecision].2 Reilly v Accident Compensation Corporation [2021] NZACC 140 [the leave judgment].3 District Court decision, above n 1, at [54].4 At [54].not causative of the serious effects of the syndrome on Mr Reilly, nor did the delay intreatment increase the severity of the effects of the syndrome.[6] Therefore, the focus of the appeal in the District Court was whether thetreatment failure, being the delay in treatment, was causative of the severity ofMr Reilly's tetraplegia or of the GBS/neurological injury he suffered. That is also thefocus of the present appeal.[7] On 17 September 2021, the District Court granted leave to appeal to theHigh Court against the District Court decision. The question of law was formulatedas follows:5Did the District Court misconstrue the test for causation and/or incorrectlyapply that test in relation to the treatment injury claim under ss 20(2)(b) and32?Background[8] The background was set out in some detail in the District Court decision. TheCorporation accepted that the treatment delay which could amount to a treatmentinjury for the purposes of cover under the Accident Compensation Act 2001 (the Act)amounted to some seven-and-a-half to eight hours. The background was summarisedin the leave judgment as follows:6[2] By way of brief summary, the applicant who was then aged 15 hadbeen mildly unwell for several days prior to 16 January 2017. On that day heexperienced difficulty in walking and had arm weakness. Reference is madeto his legs collapsing while he was walking the dog and that he had to beassisted to his feet. At 8.05 pm on 16 January the applicant's mothertelephoned Healthcare Medical in Motueka. After quite a lengthy discussionwith the nurse no immediate steps were taken at that point for the applicant tohave a further medical assessment. Just over seven hours later at 3.22 am theapplicant's mother made a second telephone call to Homecare Medical inMotueka. In the intervening period the applicant's condition had dramaticallyworsened. He had gone to bed but in the early hours of the morning,immediately prior to this phone call, he was found on the floor unable to move.[3] An ambulance was called and at 5.05 am on 17 January 2017 he wasadmitted to Nelson hospital. After a short time including time in the intensivecare unit he was flown to Christchurch Hospital and admitted to the intensivecare unit there.5 The references are to the provisions of the Accident Compensation Corporation Act 2001.6 The leave judgment, above n 2.[4] His diagnosis at Nelson Hospital was:Lower motor neurone dysfunction - Guillain Barre Syndrome,acute motor axonal neuropathy type.[9] Mr Reilly continues to suffer from tetraplegia and requires assistance in allareas of his life.[10] Dr Balraj Singhal, who was treating Mr Reilly at the Burwood Spinal Unit,lodged a treatment injury claim with ACC on 5 October 2017. The treatment injuryclaim was based on the delayed diagnosis of GBS. The injury details were listed as"Campylobacter Guillain-Barre syndrome with clear evidence of delayed diagnosis".[11] The District Court Judge referred to Dr Singhal's comments concerning thedelay in diagnosis as follows:[41] Dr Singhal refers to the transcript from the Home Care of thetelephone consultation on 16 January 2017 which he states provides evidencethat Alex's mother provided a clear and detailed description of his progressingmotor weakness and loss of coordination together with his difficulties withwalking and other activities. He states: The transcript also confirms that in response, no advice was givento seek immediate medical attention. The central theme of the adviceprovided appears to be reassurance and encouragement to increasenutrients, particularly protein, while maintaining plenty of fluids.The symptoms and history that [Mr Reilly's mother] describedpresented a classical presentation of Guillain-Barre, or one of a rangeof other serious mental conditions involving myopathy or neuropathy,poisoning or serious metabolic disorder, any of which would havewarranted further, urgent medical investigation The initial adviceprovided by the Home Care nurse seems not only inadequate butharmful, and seeking to divert and delay the concerned family'sefforts to obtain competent medical assistance for their son.It seems likely that if the implications of symptoms had beenrecognised by a health professionals [sic] who was consulted on16 January and appropriate advice given, his already concernedparents would have immediately taken him to Nelson Hospital toarrive before 9 pm on the 16th.It also seems likely that, as happened on the subsequent day, hiscondition would have been quickly diagnosed at Nelson Hospital.Medical literature which discusses the treatment of Guillain-Barretypically emphasises the appointment of timely and accuratediagnosis following early initiation of appropriate treatment. It canbe argued that the avoidable delay in recognising the seriousness ofAlex's condition and consequent delay in commencing appropriatetreatment for Guillain-Barre contributed directly to Alex's level ofdisability.[42] In his report, Dr Singhal also included a medical article aboutGuillain-Barre syndrome.[12] The Corporation subsequently obtained a report from Dr Brian Dwyer, aninfectious disease specialist, dated 17 December 2017,7 who gave an opinion that hedid not consider it "at all likely" that any treatment (immunoglobin or plasmapheresis)administered on the evening he was diagnosed would have been likely to have keptMr Reilly out of intensive care or off a ventilator. He said it was not possible toconfidently state that it is more likely that with treatment started 12 hours earlier, therewould have been an influence on the duration of disability or resumption of mobilityor degree of independence.8[13] The Corporation also obtained advice from Dr Ian St George, a generalpractitioner, who confirmed that the homecare nurse failed to recognise Mr Reilly'ssymptoms and appropriate advice would have been immediate transfer to hospital.9Dr St George also took the view that there was no evidence that earlier treatment wouldhave improved the outcome.10[14] As a result of those medical opinions, the Corporation's Complex Claim Panelproduced a report on 22 March 2018, concluding that there was no evidence that theearlier treatment would have improved the outcome.11[15] The ACC review took place on 1 February 2019. The decision dismissing thereview was issued on 7 February 2019. The appeal to the District Court followed.[16] The District Court Judge on appeal ultimately preferred the evidence ofDr Dwyer over that of Dr Singhal and concluded that the delay in presenting to thehospital was not causative of a treatment injury. The Judge held that ACC was correctin stating "there is no evidence to suggest the delay in the diagnosis had an influence7 District Court decision, above n 1, at [48].8 At [54].9 At [56].10 At [57].11 At [67].on the outcome of the Guillain-Barre syndrome".12 The Judge therefore found that thedecision of the Corporation, dated 6 March 2018, declining the claim for cover fortreatment injury was correct.13Treatment Injury[17] "Treatment injury" is defined in s 32 of the Act. It relevantly provides:32 Treatment injury(1) Treatment injury means personal injury that is—(a) suffered by a person—(i) seeking treatment from 1 or more registered healthprofessionals; or(ii) receiving treatment from, or at the direction of, 1 ormore registered health professionals; or(iii) referred to in subsection (7); and(b) caused by treatment; and(c) not a necessary part, or ordinary consequence, of thetreatment, taking into account all the circumstances of thetreatment, including—(i) the person's underlying health condition at the timeof the treatment; and(ii) the clinical knowledge at the time of the treatment.(2) Treatment injury does not include the following kinds of personalinjury:(a) personal injury that is wholly or substantially caused by aperson's underlying health condition:(b) personal injury that is solely attributable to a resourceallocation decision:(c) personal injury that is a result of a person unreasonablywithholding or delaying their consent to undergo treatment.(3) The fact that treatment did not achieve a desired result does not, ofitself, constitute treatment injury.12 At [267].13 At [271].[18] The term "treatment" is defined in s 33 of the Act:33 Treatment(1) For the purposes of determining whether a treatment injury hasoccurred, or when that injury occurred, treatment includes—(a) the giving of treatment:(b) a diagnosis of a person's medical condition:(c) a decision on the treatment to be provided (including adecision not to provide treatment):(d) a failure to provide treatment, or to provide treatment in atimely manner:(e) obtaining or failing to obtain, a person's consent to undergotreatment, including any information provided to the person(or other person legally entitled to consent on their behalf ifthe person does not have legal capacity) to enable the personto make an informed decision on whether to accept treatment:(f) the provision of prophylaxis:(g) the failure of any equipment, device, or tool used as part ofthe treatment process, including the failure of any implant orprosthesis (except where the failure of the implant orprosthesis is caused by an intervening act or by fair wear andtear), whether at the time of treatment or subsequently.(h) the application of any support systems, including policies,processes, practices, and administrative systems, that—(i) are used by the organisation or person providing thetreatment; and(ii) directly support the treatment.(2) Subsection (1) does not affect the application of the definition oftreatment in section 6(1) for purposes other than those stated insubsection (1).(3) Subsection (2) is for the avoidance of doubt.Case law — causation[19] There must be a causal link between the treatment (or failure to treat) and theinjury. It has been accepted in case law that there is a difference between the scientificand medical view of proof and the legal view of proof, and that courts can reasonablyinfer causation in circumstances where experts may not.14[20] Two key cases relating to causation in the context of treatment injuries are theCourt of Appeal decisions in Adlam v Accident Compensation Corporation andAccident Compensation Corporation v Ambros.15[21] The Court in Adlam stated:[61] In the result, we consider the relevant provisions properly construedmean that in order for there to be treatment injury as a result of a failure toprovide treatment it is necessary to show that an alternative treatment thatwould have prevented the injury suffered could and should have been givenhaving regard to the clinical indications at the time of the alleged failure.[22] In Ambros, the Court of Appeal said that where medical evidence establishes a"possible" connection, this may be sufficient, but the question of causation isultimately one for the court to decide and the court is not bound by specialist opinion.16While the court is entitled to draw "robust" inferences in individual cases, there muststill be sufficient material which points to proof of causation on the balance ofprobabilities. A risk of causation will not suffice.17[23] Ambros has been applied in cases relating to failure to treat in both the Courtof Appeal and the High Court.18Legal principles on appeal[24] An appeal to the High Court from a District Court decision in an ACC reviewdecision is an appeal on a question of law. The approach to an appeal on a question14 See Dunn v Accident Compensation Corporation DC Te Whanganui-a-Tara | Wellington 307/03,27 November 2003; Smith v Accident Compensation Corporation DC Te Whanganui-a-Tara |Wellington 255/04, 23 August 2004 at [26]; and W v Accident Compensation Corporation [2018]NZHC 937 at [56].15 Adlam v Accident Compensation Corporation [2017] NZCA 457, [2018] 2 NZLR 102; andAccident Compensation Corporation v Ambros [2007] NZCA 304, [2008] 1 NZLR 340.16 Accident Compensation Corporation v Ambros, above n 15, at [67]–[68].17 At [70].18 See for example Cumberland v ACC [2013] NZCA 590 at [44]–[50]; Robertson v AccidentCompensation Corporation [2015] NZHC 2489 at [41]; Dela Rosa v Accident CompensationCorporation [2019] NZHC 2657 at [59]–[61]; Accident Compensation Corporation v Stanley[2013] NZHC 2765 at [6]; W v Accident Compensation Corporation, above n 14; and Thompsonv Accident Compensation Corporation [2015] NZHC 1640 at [38]–[39].of law was set out in the judgment of Heath J in Accident CompensationCorporation v Stanley: 19(a) An appeal on a question of law[33] On appeal to this Court, the question is whether the District CourtJudge made errors of law of the type formulated by Judge Beattie. There aredifferent types of legal error. They are addressed in differing ways.[34] For present purposes, the nature of a "question of law" can be gaugedby reference to the analogous provisions of the Employment Relations Act2000. Delivering the judgment of the Supreme Court in Bryson v Three FootSix Ltd, Blanchard J observed:(a) An appeal cannot be regarded as being brought on a question oflaw where the fact-finding Court has merely applied law which ithas correctly understood to the facts of an individual case.Provided that the Court has not overlooked any relevant matter, ortaken account of some matter which is irrelevant to the properapplication of the law, the conclusion is a matter for the fact-finding Court, unless clearly insupportable.(b) The ultimate conclusion of a fact-finding body can sometimes beso insupportable, or so clearly untenable, as to amount to an errorof law. That will occur when proper application of the law requiresa different answer. Such cases will arise rarely; for example, cases"in which there is no evidence to support the determination", "onein which the evidence is inconsistent with and contradictory of thedetermination" or "one in which the true and only reasonableconclusion contradicts the determination".(c) It does not matter whether an appellate Court would have reacheda different conclusion on the evidence. The issue is whether thedecision under appeal was a permissible option.(d) An error concerning a particular fact which is only one element inan overall factual finding cannot be said to give rise to a finding of"no evidence" where there is support for the overall finding inother portions of the evidence. It could, however, lead orcontribute to an outcome that is insupportable.[35] Mr Coates referred to the judgment of the Supreme Court in Austin,Nichols & Co Inc v Stichting Lodestar, on the basis that, he contended,this was an appeal by way of rehearing. With respect, Austin, Nicholsis not applicable. While s 162(5) of the Act (s 162 confers the rightof appeal to this Court) incorporates by reference certain provisionsof the High Court Rules and the District Courts Act 1947, none ofthem turn what s 162(1) describes as an appeal on a question of lawinto one by way of rehearing. On an appeal brought on a question oflaw, an appellant is confined to the grounds of attack to which theSupreme Court referred in Bryson, as confirmed in its later decisionin Vodafone New Zealand Ltd v Telecom New Zealand Ltd.19 Accident Compensation Corporation v Stanley, above n 18, at [33]–[35] (citations omitted).The appellant's case[25] The appellant says the facts here present a textbook example of where theCourt could have found that the treatment injury (failure or delay to treat) caused theseverity and longevity of the damage caused to Mr Reilly by the syndrome.[26] Mr Miller, for the appellant, said the Court could have found legal causationon the medical evidence available which could establish the possibility of the linkbetween the accident and the injury, or the more severe and long-lived effects of GBS.In particular, Mr Miller relied on Ambros to argue that the District Court Judge failedto step through the process or tests set out in that case. He said that evidence of awell-qualified medical specialist was available which would provide the likelymedical causation for the injury. He was referring to the evidence of Dr Singhal, whocommenced treating Mr Reilly when he arrived at the Burwood Spinal Unit on29 March 2017.20[27] Mr Coates, for the Corporation, said he had been under the impression that theappellant would also argue that there should be a different test for causation to thatlaid out by the Court of Appeal in a number of decisions.21 This would allow for aless stringent or lower standard for causation in the case of "rare, severe andbiologically not well understood by medical science" conditions such as GBS.22[28] Mr Miller indicated he had not intended to argue for a different test forcausation in such situations. He advanced the appeal on the basis of the terms of theapproved question of law stated above, which was whether the District Courtmisconstrued the test for causation and/or incorrectly applied that test in relation tothe treatment injury claim.23[29] Mr Coates, for the respondent, said the Judge had correctly applied the legaltest for causation, as articulated by the Court of Appeal. While ultimately20 District Court decision, above n 1, at [32]–[33].21 Atkinson v Accident Rehabilitation Compensation and Insurance Corporation [2002] 1 NZLR 374(CA); and Accident Compensation Corporation v Ambros, above n 15.22 The leave judgment, above n 2, at [21].23 At [8].Her Honour's reasoning was succinct, she had nevertheless traversed the relevant testsand applied them to the evidence before her.The test for causation[30] Mr Miller referred to Adlam, which established that a failure to providetreatment or to provide treatment in a timely manner could amount to a treatmentinjury and attract cover, and that while not requiring a finding of negligence, atreatment injury will have only occurred where there has been some departure from astandard "and that departure has caused a person injury".24 Counsel agreed thatAmbros and the Court of Appeal earlier decision in Atkinson were the leading Courtof Appeal cases governing the issue of causation in circumstances such as the present.[31] The earlier case of Atkinson v Accident Rehabilitation Compensation andInsurance Corporation,25 held that it was for the complainant to prove causation.26The Accident Compensation legislation, the Court of Appeal in Atkinson said, focuseson outcomes and not risk of injury or potential for injury.27 The Court went on to saythat for cover to exist, the risk must be realised.[32] The Court of Appeal in Ambros started its analysis with Atkinson. It said:[12] The main common law development relied on by the appellant inAtkinson was a shift in focus from the cause of the injury itself to the risk ofinjury resulting from a wrongful act or omission. It was argued that, wherethis is the case, all the plaintiff has to establish is that the defendant's conductwas at least capable of causing or aggravating the damage and did in factmaterially increase the risk of that damage.[13] This Court in Atkinson said it was satisfied that the appeal must fail.It held that it was for the claimant to prove causation – see at [23]. The Courtsaid, at [24], that the accident compensation legislation focuses on outcomesand not risk of injury or potential for injury. For cover to exist, the risk mustbe realised. All that had been proved in the particular case was that there wasa possibility (or risk) that the medical misadventure (sub-optimal care duringan operation at Wanganui Hospital) contributed to the infant's injury (braindamage). There may have been other factors also that could have caused thedamage. Indeed, the evidential difficulty was more serious. The claimant hadnot even proved injury. Given his age, experts were not able to assess whether24 Adlam v Accident Compensation Corporation, above n 15, at [65].25 Atkinson v Accident Rehabilitation Compensation and Insurance Corporation, above n 21.26 At [23].27 At [24].or not the infant's development had been normal before surgery and becomeslow after it or whether his development was always going to be slow.[14] The Court went on to say that it is not sufficient to prove that themedical misadventure risked causing an injury. It must be proved to have doneso and to the usual civil standard of balance of probabilities. The Court heldthat to accept a lesser standard of increased risk or to adopt a reverse onusapproach does not accord with the statutory scheme. The public policyconsiderations, which had led to the common law developments relating tocausation, were rejected as being inapplicable to a statutory no faultcompensation scheme which is outcome and not risk focused - see at [25] ofAtkinson.[15] While the High Court in this case accepted that causation had to beproved by Mr Ambros, it required him to prove only a close temporal linkbetween the injury and the medical misadventure and to exclude inevitabilityof injury and supervening cause. This effectively means that, under the HighCourt test, as long as the injury occurred in close proximity to the medicalerror, a claimant would have proved causation, absent supervening cause, ifthere was as little as a one per cent chance of survival had the medical errornot occurred.[16] This falls squarely within the proposition rejected by this Court inAtkinson that a risk or possibility that the medical misadventure caused theinjury suffices to prove causation, absent evidence to the contrary. The HighCourt test does not, therefore, accord with that laid down by this Court inAtkinson. In order to uphold the High Court decision, we would need to departfrom Atkinson. The next issue, therefore, is whether we should do so.(emphasis added)[33] The Court then went on to confirm that Atkinson had been correctly decided.28As the Court said:29 In ordinary usage, one would not normally say that an injury was causedby medical error when that injury was highly likely to have occurred withoutthe error.[34] The Court went on to set out the test for causation as follows:What is the traditional test for causation?[22] Atkinson states that causation must be proved on the balance ofprobabilities and that a risk of injury does not suffice. The judgment was,however, relatively brief and did not discuss how the courts should assesscausation. We discuss the causation issue in more depth below so as to give aproper framework for any decision on causation in this case. In doing this weare also attempting in some measure to answer the plea for more guidance oncausation principles by Associate Professor Joanna Manning in Skegg and28 Accident Compensation Corporation v Ambros, above n 15, at [18].29 At [18].Paterson (eds) Medical Law in New Zealand (2006) at [24.8.1], although theframework in this case can only be indicative for future cases as it may notassist in different factual circumstances.[23] Atkinson also held that the developments in the common law(including loss of chance) are not applicable to the accident compensationregime. Again, there was no detailed explanation of why that is the case. Itis helpful to discuss the reasons that the earlier developments are not relevantunder an accident compensation regime in more depth in this judgment as thatputs the later developments since Atkinson in context. We have held, at [19],that those later developments do not give cause to review Atkinson. Thediscussion of those developments set out below provides a fuller explanationfor that decision.[35] The Court of Appeal in Ambros went on to undertake a detailed analysis ofcausation and common law developments in the area.30 In the course of thatdiscussion, the Court of Appeal noted that modifying the traditional test of causationto deal with evidential uncertainty would arguably create as many difficulties as itsolves because of the uncertain scope and the absence of any overarching principle.31[36] The Court of Appeal then turned to the call to extend the loss of a chanceprinciples to cover cases of medical negligence.32 It commented:[38] The loss of a chance of a better medical outcome often arises in casesof delayed, missed or wrong diagnosis leading to a deterioration in thepatient's condition. What must be determined is whether the damage is aresult of the doctor's fault or the normal outcome of the pre-existing condition– see Laferrière v Lawson (1991) 78 DLR (4th) 609 at 657(h) – 658(a) (SC).The answer, on traditional causation principles, will depend on the patient'sprognosis at the time the correct diagnosis should have been made. If thepatient was at that time more likely than not to recover if properly diagnosedand treated, then the faulty diagnosis will be treated as causative. Otherwiseit will not be. If it is treated as causative then full damages are recovered andthere is no discounting for the chance (which could be up to 49 per cent) thatthe negligence did not cause the deterioration. If it is not found to be causative,then the plaintiff fails to recover at all.(emphasis added)[37] It concluded that whatever the future developments in loss of chance in otherjurisdictions, "the loss of chance analysis seems to us to be incompatible with the30 At [24]–[36].31 At [35].32 At [37].accident compensation regime."33 In relation to the loss of a chance developments,the Court of Appeal noted:34 In terms of the causation principles set out in Atkinson, any risk must berealised in the occurrence of a personal injury and the personal injury must beproved to have been caused by the risk factor involved. In keeping with thisprinciple, if the omission to treat causes an identifiable added injury, coverwould be available for that injury.[38] The Court of Appeal in Ambros then moved on to examine how the courts hadotherwise dealt with the difficulty of proof and uncertainty. It noted:(a) The frequent difficulty in establishing a causal link between medicalerror and injury because of scientific uncertainty over the causalmechanism.35(b) The term "burden of proof" has been used in two quite distinct senses.36The first is a reference to the legal burden. This must be proven in orderto win the case. The second is the evidential burden. The evidentialburden, in the first sense, means the burden of adducing evidence on anissue "on pain of having the trial Judge determine the issue in favour ofthe opponent."37 The second sense in which evidential burden is usedis the burden resting on a party who appears to be at risk of losing on agiven issue at a particular point in the trial. That involves a tacticalevaluation of who is winning at a particular point, which can shiftdepending on the trial dynamic. That is often referred to as the "tacticalburden".38(c) The switching of the legal burden onto the defendant was rejected inAtkinson.3933 At [46].34 At [46].35 At [53].36 At [55].37 At [55].38 At [55].39 At [56].(d) The shifting of the evidential onus has met with greater acceptance.40Where for example the facts lie particularly within the knowledge ofthe defendant, "very little affirmative evidence on the part of theplaintiff will justify the drawing of an inference of causation in theabsence of evidence to the contrary and even though positive orscientific proof of causation has not been adduced".41 As the Courtnoted:42Even if some evidence to the contrary is adduced by thedefendant, the trial judge is entitled to take account LordMansfield's famous precept in Blatch v Archer :43It is certainly a maxim that all evidence is to beweighed according to the proof which it was in thepower of one side to have produced, and in the powerof another to have contradicted.(e) Adopting the term "tactical burden", the Court of Appeal noted thatLord Mansfield's maxim had been applied in New Zealand in a numberof different contexts.44(f) The legal burden to prove causation, in an accident compensation caseremains with the claimant and does not shift to the Corporation.45Atkinson does not rule out a shift of the evidential burden to theCorporation.46[39] The Court of Appeal then moved on to discuss inferences in a passage of thejudgment on which Mr Miller relied. The Court said:INFERENCES[65] The requirement for a plaintiff to prove causation on the balance ofprobabilities means that the plaintiff must show that the probability ofcausation is higher than 50 per cent. However, courts do not usually undertakeaccurate probabilistic calculations when evaluating whether causation hasbeen proved. They proceed on their general impression of the sufficiency of40 At [57].41 At [59].42 At [59] (footnote added).43 Blatch v Archer [1774] 1 COWP, 98 ER 969 at 970.44 Accident Compensation Corporation v Ambros, above n 15, at [62].45 At [63].46 At [63].the lay and scientific evidence to meet the required standard of proof - seeKhoury at 35. The legal method looks to the presumptive inference which asequence of events inspires in a person with common sense 47[66] The legal approach to causation is different from the medical orscientific approach. In March v Stramare, Mason CJ at 509 in the High Courtexplained that the scientific concept of causation has been developed in thecontext of explaining phenomena by reference to the relationship betweenconditions and occurrences whereas in law problems of causation arise in thecontext of ascertaining or apportioning legal responsibility for a givenoccurrence. At law the cause is not the sum of the conditions which are jointlysufficient to produce the occurrence.48 [67] The different methodology used under the legal method means that acourt's assessment of causation can differ from the expert opinion and courtscan infer causation in circumstances where the experts cannot. This hasallowed the court to draw robust inferences of causation in some cases ofuncertainty – see at [32] above. However, a court may only draw a validinference based on facts supported by the evidence and not on the basis ofsupposition or conjecture49 Judges should ground their assessment ofcausation on their view of what constitutes the normal course of events, whichshould be based on the whole of the lay, medical, and statistical evidence, andnot be limited to expert witness evidence 50[68] Spigelman CJ in Seltsam said that the only time that a Judge is notable to draw a robust inference of causation are cases where medical sciencesays that there is no possible connection between the events and the injury ordeath – see at 275. If the facts stand outside an area in which commonexperience can be the touchstone, then the Judge cannot act as if there were aconnection. However, if medical science is prepared to say that there is apossible connection, a Judge may, after examining all the evidence, decide thatcausation is probable. He referred in this regard to the comments of HerronCJ in EMI (Australia) Limited v BES at 242. In the case at hand Spigelman J,reversing the trial judge's findings, did not consider the evidence sufficient toinfer causation. He was joined in that view by Davies A-JA. Stein JAdissented.47 The Court cited Peter Greenberg "The Cause of Disease and Illness: Medical Views andUncertainties" in Ian Freckelton and Danuta Mendelson Causation in Law and Medicine(Routledge, Oxford, 2002) 38 at 52; and March v E & M H Stramare Pty Ltd (1991) 171 CLR 506at 509 per Mason CJ, which was approved in Sew Hoy & Sons Ltd (In Receivership and inLiquidation) v Coopers & Lybrand [1996] 1 NZLR 392 (CA) at 407 per Thomas J, Smith v StateInsurance Ltd [1993] DCR 947 at 958–959, and Ross v Accident Compensation Corporation DCTe Whanganui-a-Tara | Wellington AI573/00, 23 August 2001.48 The Court then referred to Seltsam Pty Ltd v McGuiness (2000) 49 NSWLR 262 at 286 perSpigelman CJ and at 294 per Stein JA; Laferrière v Lawson [1991] 1 SCR 541, (1991) 78 DLR(4th) at 656–657 per Gonthier J; Snell v Farrell [1990] 2 SCR 311, (1990) 72 DLR (4th) 289 at300 per Sopinka J; Chappel v Hart (1998) 195 CLR 232 at 238 per Gaudron J and at 255 perGummow J; Naxakis v West General Hospital (1999) 197 CLR 269 (1999) 162 ALR 540 perGaudron J; and EMI (Australia) Ltd v BES [1970] 2 NSWR 238 at 242 (CA). The Court alsoreferred to Jane Stapelton "Scientific and Legal Approaches to Causation" in Ian Freckelton andDanuta Mendelson Causation in Law and Medicine (Routledge, Oxford, 2002) 14 at 14; andPersonal Injury in New Zealand at [IP30.04] and [IP155.07].49 The Court cited Jones v Great Western Railway Co (1930) 47 TLR 39 at 45; and Smith v AucklandHospital Board [1965] NZLR 191 (CA) at 214 per McGregor J and at 220 per Gresson J.50 The Court cited Lara Khoury Uncertain Causation in Medical Liability (Hart Publishing, Oxford,2006) at 203; and at 39–43 and 143–228 for a "more detailed discussion on inferences".[69] We agree that the question of causation is one for the courts to decideand that it could in some cases be decided in favour of a plaintiff even wherethe medical evidence is only prepared to acknowledge a possible connection.51[70] Finally on this topic, we note that the generous and unniggardlyapproach advocated in Harrild v Director of Proceedings [2003] 3 NZLR 289at [19] (CA) per Elias CJ, at [39] per Keith J and at [130] per McGrath J wasused by the High Court in this case to modify the causation test. This, in ouropinion, is not an appropriate application of the principle, given the plainwords of the 1998 Act and the rejection of the increased risk test in Atkinson.The generous and unniggardly approach referred to in Harrild may, however,support the drawing of "robust" inferences in individual cases. It must,however, always be borne in mind that there must be sufficient materialpointing to proof of causation on the balance of probabilities for a court todraw even a robust inference on causation. Risk of causation does not suffice.[40] The Court of Appeal in Ambros then went on to note that it was not unusual inmedical negligence cases for the complainant to be able to point only to a statisticallink between particular events in the injury.52 The Court also set out key principlesespoused by Sir Austin Bradford Hill referred to in the Federal Judicial Centre'sReference Manual on Scientific Evidence (1994).53 Those key principles assist in theanalysis of statistics and research. They highlight the following factors: statisticalassociation; dose response effect; temporality; consistency (between epidemiologicalstudies); analogy; biological coherence; experimental evidence; and specificity.54[41] The Court of Appeal cautioned about undue reliance on statistical evidence.There was always a risk that it gave an illusion of precision which was actuallylacking.55 The Court said it had not heard argument on the Hill factors but that it mightbe that they "deserve further consideration to see if they might provide a possible51 The Court referred to Dais v Accident Compensation Corporation DC Te Whanganui-a-Tara |Wellington 178/2002, 5 August 2003; Smith v State Insurance Ltd, above n 47, at 959; and Estateof Albert Francis McQueen v Accident Compensation Corporation DC Kirikiriroa | Hamilton190/2005, 28 June 2005.52 Accident Compensation Corporation v Ambros, above n 15, at [71].53 At [74]. The Federal Judicial Centre's Reference Manual on Scientific Evidence (1994) in turnrefers to the criteria formulated by Sir Austin Bradford Hill, then Professor Emeritus of MedicalStatistics of the University of London, in his Presidential Address to the Section of OccupationalMedicine, "The Environment and Disease: Association or Causation?" (1965) 58 Proc R SocMedicine 295, which are also discussed with approval in Ian Freckelton "Epilogue: Dilemmas inProof of Causation" in Ian Freckelton and Danuta Mendelson Causation in Law and Medicine(Routledge, Oxford, 2002) 429 at 443–444.54 Accident Compensation Corporation v Ambros, above n 15, at [75].55 At [76].framework for assessing the weight to be applied to certain statistical evidence in somecases."56[42] The Court of Appeal then went on to discuss proximity, with particularreference to vaccination cases, where if a person suffers an allergic reaction just afterbeing injected and that reaction is a known risk from that injection then "in the absenceof a supervening cause, a court would almost certainly infer causation."57 However,it would not suffice where, for instance, the reaction was not a known possible result,particularly when there were other possible causes of the reaction.58[43] The Court of Appeal then examined the evidence in causation that had beenbefore the High Court in that case, in particular an article on the effectiveness orotherwise of any possible treatment which was cited in evidence before the Court. TheCourt of Appeal concluded that, given the limitations on the statistical evidencecontained in that article, it could not necessarily be assumed that treatment ofMrs Ambros would have allowed her to survive any longer than she did.59[44] In the face of a suggested modified causation test put forward by counsel todeal with the unfairness of requiring a claimant to prove causation in cases of rarediseases where scientific uncertainty was often at its greatest, the Court in Ambrosrejected a formulation based on an obligatory presumption that the courts must make"as a matter of law, when certain facts exist and in the absence of conflictingevidence".60[45] The Court of Appeal noted:[80] While a liberal view should be taken of when a tactical burden maypass to the Corporation, we do not consider that the scheme of legislationwould allow a presumption of causation to arise in circumstances where theevidence would not (without the presumption) reach the required standard forproving causation Even the relaxation of causation requirements has beenonly in very limited circumstances.56 At [76].57 At [78].58 At [78].59 At [105].60 At [79].[46] The Court of Appeal rejected a modified test in cases of scientific uncertainty.Consistent with that, the appellant does not challenge the test of causation establishedby the Court of Appeal.[47] In Ambros, the Court of Appeal held that the High Court did not apply thecorrect test for causation and therefore referred the matter back to the High Court. Itsaid:61[102] In this case it is accepted that there were only two possible causes ofMrs Ambros' death. Either she died as a result of her underlying condition(SCAD) or she died as a result of medical error by a failure to diagnose,monitor and treat her appropriately. In order to succeed, Mr Ambros isrequired to prove the latter on the balance of probabilities. Has he done so?[103] While its factual findings were sufficient for the High Court toconclude that causation was proved on the basis of its test (as set out at [4]above), finding that it was possible that Mrs Ambros may have been saveddoes not equate to a finding that she would more likely than not be alive hadit not been for the medical errors made.[104] The issue therefore is whether Mr Ambros is right and the evidencebefore the High Court proved causation even in accordance with the correcttest. As Mr Gray pointed out, on the basis of the statistics in the article referredto above at [93], Mrs Ambros had at least a 51 per cent chance of survival.This means that her survival was more probable than not. Indeed, Mr Graysubmits that, as Mrs Ambros had survived for six days without diagnosis ortreatment, her chance of survival (based on the evidence in that article whereall who died did so within four days) was arguably even higher.[105] The High Court, because of its formulation of the test of causation,made no findings based on the statistical evidence contained in the article.Both the pathologist and Dr Hart, however, appeared to accept in evidencethat Mrs Ambros' case could be equated to those discussed in the article.There are limitations with the statistics. First, the sample used in the articlewas small but that appears to be because the condition is so rare. Indeed,Dr Hart in evidence suggested that the article covered all reported pregnancyrelated cases at the time. Thus the sample is not skewed even if the numbersare small. Secondly, and most importantly, however, the relationship betweentreatment and survival is not clear. For a start, there does not appear to be arecognised preferred treatment for the condition and, apart from the articlewhich refers to good results in some cases from treatment, there was noevidence before the Court on the effectiveness or otherwise of any possibletreatment. Further, while it is safe to assume that those whose conditionpresented as sudden death had not had treatment, that cannot be assumed forthe others who died. Neither can it necessarily be assumed that those whosurvived for more than four days did so because of any treatment administeredrather than because of the natural course of the condition itself.61 At [102]–[105].[48] Atkinson said that causation must be proved on the balance of probabilities andthat a risk of injury does not suffice.62 Ambros confirmed that was the correct test andwent on to discuss how the courts should assess causation.63 It provided a frameworkfor more guidance on causation principles but noted the framework could only beindicative for future cases as it may not assist in different factual circumstances.64[49] The starting point under that framework is, did the Judge in the District Courtapply the correct test for causation? I now go on into some detail to analyse theDistrict Court decision.The District Court decision — what did the Judge do?[50] The judgment uses the headings: Background; ACC claim; Review; The Law;The Position of the Appellant; Appellant Submissions at the Hearing; The Position ofthe Respondent; Respondent Submissions at the Hearing; Counsel for the appellant inreply; Discussion; The Present Application; Conclusion; and Result.[51] One of the points brought up by the appellant is that the actual analysis in thejudgment was relatively brief. It ran to about 37 paragraphs from the headings "ThePresent Application" to the end of "Result". However, the analysis draws on theinformation in the preceding 236 paragraphs, which cover the facts and the law,referring to the relevant medical reports and the analysis by the Reviewer.65 Inparticular, the Judge sets out the Court of Appeal causation test indicating that robustinferences of causation can be drawn and that a Court could not infer causation whenthe science says it is "not possible."66 The Judge also quoted from Ambros to the effectthat the question of causation was one for the court to decide and she noted that "[t]hedifferent methodology used under the legal method means that a court's assessment ofcausation can differ from the expert opinion and courts can infer causation incircumstances where the experts cannot."6762 At [22].63 At [18].64 At [22].65 At [80] onwards, setting out the law, including the relevant case law, in particular AccidentCompensation Corporation v Ambros, above n 15.66 At [113].67 At [114].[52] Importantly, the Judge noted, in referring to counsel's arguments, the passagesin Ambros in relation to the drawing of causal inferences and the need to bear in mindthat there was sufficient material pointing to proof of causation on the balance ofprobabilities, for a Court to draw even a robust inference of causation.68 As the Judgeobserved, mere risk of causation does not suffice.69 The Judge cited Ambros referringto the requirement for a plaintiff to prove causation on the balance of probability. Theplaintiff must show the probability of causation is higher than 50 per cent.70 TheJudge, however, acknowledging that the Court could draw robust inferences ofcausation in cases of uncertainty, quoted the following passage from Ambros:71 However, a court may only draw a valid inference based on facts supportedby the evidence and not on the basis of supposition or conjecture [53] The Judge had firmly in mind the correct test of causation. She remindedherself of the decision in Ambros as she came to analyse causation in her judgment.72[54] I now turn to the Judge's review of the evidence. She noted that Dr Singhaltreated Mr Reilly at the Burwood Spinal Unit, presumably since his arrival on29 March 2017.73 On 5 October 2017, Dr Singhal lodged a treatment injury claimwith ACC on Mr Reilly's behalf for delayed diagnosis of GBS. In the injury details,it was described as "Campylobacter Guillian-Barre Syndrome with clear evidence ofdelayed diagnosis".74 The Judge set out the background from an undated letter byDr Singhal, attached to the treatment injury claim, in which Dr Singhal recounts thebackground as provided by Mr Reilly, and noted Dr Singhal's comments that a"differential diagnosis of Guillian-Barre syndrome, acute motor axonal neuropathytype was quickly arrived at".75 The Judge then recorded Dr Singhal's conclusion, inrelation to treatment delay, that there was a nine to 10-hour delay as a result of theHelpline advice.76 Dr Singhal went on to state:7768 At [150].69 At [150].70 At [150], citing Accident Compensation Corporation v Ambros, above n 15, at [65], [67] and [70].71 At [150], citing Accident Compensation Corporation v Ambros, above n 15, at [67].72 At [256].73 At [32]–[33].74 At [33].75 At [35]–[37].76 At [40].77 At [41]. Medical literature which discusses the treatment of Guillian-Barre typicallyemphasises the appointment of timely and accurate diagnosis following earlyinitiation of appropriate treatment. It can be argued that the avoidable delayin recognising the seriousness of Alex's condition and consequent delay incommencing appropriate treatment for Guillian-Barre contributed directlyto Alex's level of disability.[55] Her Honour noted that Dr Singhal referred in his report to a medical articleabout GBS by Professor Hugh J Willson, Professor Bart C Jacobs and Professor PieterA van Doorn.78[56] The Judge then went on to note that the Corporation subsequently obtained areport from Dr Brian Dwyer, an infectious disease specialist, dated 17 December2017.79 Dr Dwyer stated the specific question required to be answered was:80ACC is wanting to determine if the treatment had been given soon after theinitial call on 20:05 hours on 16/1/2017, would it have altered the severity ofthe outcome.[57] No issue is taken with the accuracy of the Judge's recitation of Dr Dwyer'scomments, as follows:81[53] Dr Dwyer states:The claim being asserted is that the delay in initial referral to thehospital related in a worsening of Alex's condition. Indeed, it seemsthat Alex spent three months on a ventilator but still required 24 hourcare and has a tetraplegia equal to a person with spinal cord lesion atthe cervical spine level of C4.[54] Dr Dwyer also answers a number of questions and states:1. There is no doubt the young man had developed a typicalacute motor axonal neuropathy without significant sensorysymptoms (GSB [sic]) in association with a bout ofcampylobacter diarrhea [sic].2. When an infection agent can be identified it is morecommonly referred to as campylobacter jejuni/coligastrointestinal infection, usually diarrhoea. Usually about athird of GBS cases can be linked to previous, recentcampylobacter infections.78 At [42] and n 2.79 At [48].80 At [49].81 Emphasis in original.3. The tempo of the onset of symptoms in GBS is an importantfactor in determining the outcome. Onset over days is morelikely to be limited. On the other hand rapid onset over hoursor less than a day is often associated with more extensiveparalysis and indeed a patient may be well in the morning anddead by the evening because of respiratory paralysis. Alexfalls into the more severe group with rather rapid onset.4. Campylobacter jejuni/coli associated GBS is more commonlyassociated with severe and prolonged disease, requiringhospitalisation compared to GBS not associated withcampylobacter. Campylobacter GBS is more likely to behospitalised, more likely to require intensive care, more likelyto require ventilation, will stay in hospital longer, and morelikely have a residual disability.5. The advice given to Alex's mother did not reflect well on thetraining of the nurse who provided it. Early recognition of thetempo of a paralysing illness is the key to ensuring survival.If Alex had not managed to text his parents from his room at3 am then the outcome may have been fatal. Advice at 8pmon the previous evening would have brought him to hospitalimmediately. The 2 hour delay by ambulance would not havehelped if his respiratory failure were progressing even morequickly. Rapid onset of the weakness and paralysis in thecontext of ongoing diarrhoea is highly suggestive of a severeand even life threatening form of GBS.6. The prediction of the final outcome of Alex's illness must beguarded. He may show more improvement over the next 2 or3 years, although there could be some residual disability.7. I do not consider it all likely that any treatment(immunoglobin or plasmapheresis) administered that eveningwould have been likely to have kept Alex out of the intensivecare or off the ventilator. It may have had an influence onduration of disability or resumption of mobility or degree ofindependence, but it is not possible to confidently state that itis more likely that with treatment started 12 hours earlier. Thedata is just not there.[55] Dr Dwyer also refers to three publications including the articlereferred to by Dr Singhal.[58] Further advice, dated 21 February 2018, obtained by the Corporation fromDr Ian St George, a General Practitioner, was recorded by the Judge as follows:82[57] Dr St George noted the history, which was already covered inDr Dwyer's report and answered the following questions:82 Emphasis in original.1. In your opinion was the initial phone call advice given by HomeCare Medical appropriate given the history from his mother,please explain.No. The nurse failed to recognise that the symptoms presented byMs Reilly [sic] were neurological and important, and so instead oftriaging using an appropriate algorithm, she used a general one thatasked irrelevant questions and reached the wrong disposition. Itappears she did seek help from a more senior clinician but such helpwas not available.2. If not what advice should have been given.The appropriate advice would have been to immediate transfer tohospital. Correct choice of algorithm would have resulted in adisposition of "urgent review within 2 hours" according toMs Gannon's review of the call.3. Do you have any other comments.I agree fully with the conclusions of Sharryn Gannon, clinical directorof Home Care Medical and Dr Dwyer's comments and conclusions.I would add that the telephone triage is a difficult skill and that backup by senior clinicians is necessary at all times. It is disappointingthat this was not available and that Ms Gannon did not comment onit.There is no evidence that earlier treatment would have improved theoutcome. The Cochrane review found only that "treatment within 7days is more effective" and that "Plasma exchange is initiated as earlyas possible but up to 30 days from the onset of the weakness.[58] He also refers in his references to an article by Mathew Harms, MD.83[59] The Judge then went on to note that the Corporation completed a TreatmentInjury Cover Decision Tool relating to the delay in the diagnosis of GBS relating intetraplegia.84 The report sets out the narrative leading to the diagnosis of GBS and theview of Mr Reilly's mother that the delay had determined the poor outcome forMr Reilly who was in Burwood as a tetraplegic.85[60] The Judge noted that the ACC report includes quotes from the reports providedby Dr Dwyer and Dr St George. The Judge set out the conclusion in the report asfollows:83 Inpatient management of Guillain-Barre syndrome. Neurohospitalist. 2011 apr; 1(2); 78-74.84 District Court decision, above n 1, at [59].85 At [61].[63] In conclusion, the report states:ACC acknowledges that the initial advice given by Home CareMedical was not recognising the neurological, aspects of thesymptoms. This is noted both by Homecare Medical and the externalmedical advisor Ian St George.However, ACC has been unable to identify any damage or harm as aresult of the delay of diagnosis.Infectious disease consultant, Dr Brian Dwyer cannot confirm that theearlier treatment from the Guillain-Barre would have had anyinfluence on the outcome of this case.ACC therefore declined the claim for cover as there is no evidence tosuggest the delay in the diagnosis has had an influence on the outcomeof the Guillain-Barre syndrome.[61] The Judge recorded that a report was also obtained from the Corporation'sComplex Claim Panel (the Panel), dated 22 March 2018, which set out the informationin respect to the events and referred to the infectious diseases advice.86[62] The Judge noted that the Panel had concluded there was no evidence that anytreatment administered earlier that evening would have improved the outcome. TheCochrane review found only that "treatment within 7 days is the most effective", andthat "Plasma exchange is initiated as early as possible but up to 30 days from the onsetof weakness".87 The conclusion of the Panel was set out by the Judge as follows:[68] In conclusion the Panel states:The legal issue is not a delay in diagnosis, but whether a failure totreat or to provide treatment in a timely manner has meant that thediagnosis could and should have been made sooner than was done.There is Guillain-Barre – this was established on 17/1/2017.Campylobacter history is significant to how the Guillain-Barresyndrome has panned out.The panel agreed that the phone call consult at 200 hours on 16/1/2017could and should have recognised the significant neurologicalsymptoms being conveyed and so gone down a protocol to accountfor the neurological symptoms, which the outcome would have beento seek urgent review within 2 hours. However, if it was seen soonerthan the outcome still the same would have happened. There has notbeen a personal injury caused by treatment. The outcome in this caseis because of Guillain-Barre syndrome.86 At [64].87 At [67].[69] The Panel, in conclusion state:Panel agreed that the telephone consult at about 2000 hours on16/01/2017 could and should have recognised the significantneurology symptoms being conveyed and so the gone down a protocolto account for the neurological symptoms, which the outcome wouldhave been to advise to seek urgent review within two hours. However,if was seen sooner than the outcome still is the same that hashappened. There has not been a personal injury caused by treatment.The outcome in this case is because of Guillain Barre Syndrome.[63] On 26 March 2018, the Corporation declined cover on the basis it did not meetthe criteria for a treatment injury. A review of the Corporation's decision was filed on6 April 2018. The Judge noted that before the review hearing, a further report wasprovided by Dr Singhal, dated 26 November 2018.88[64] The relevant parts of Dr Singhal's report were also set out by the Judge asfollows:89[74] Dr Singhal provides information in respect to his credentials asClinical Director of Adult Rehabilitation Services at Burwood Hospital inChristchurch and that he is a Spinal Rehabilitation Specialist and has workedin the field since 2003. He notes:I have a special interest in acute spinal cord injury and neurologicalsequelae of neurological conditions such as Guillain-Barre syndrome. I understand ACC has agreed there was a delay in diagnosissecondary to the incorrect advice given over the phone to Alex'smother on 16/1/2017 but do not agree that this caused him to haveworse neurological damage and it would not have prevented him tohave his severe degree of GBS. I have considered my previous report,ACC serious injury panel report and opinion, literature review onGBS and the Burwood Spinal Unit experience dealing with seriouscases of GBS who come to the spinal unit for rehabilitation andpreparing this report and answering your questions.1. On the balance of probabilities or to what extent, if anydid the delay in treatment contribute to Alex'sneurological injury. Please discuss. Could the neurological sequelae and the ventilation beprevented if the diagnosis had been made earlier, the answerto this is probably not as pointed out by Dr Dwyer in hisopinion but could the degree of disability and time inventilation be shortened. The answer is that probably thecourse of the immunity antibody mediated damage to the88 At [71]–[73].89 Citations omitted.nervous system would be less and the recovery from theaftermath of the disease and time on ventilation may havebeen shortened. This may have meant Mr Reilly could be lessdisabled being able to walk independently or with some aid.2. If you have not already addressed this above, do you agreewith Dr St George that "there is no evidence that earliertreatment would have improved the outcome."I disagree with Dr St George, there is no evidence that earliertreatment would have improved the outcome.There is enough evidence in the literature to say that theearlier the treatment in the form of plasmapheresis or IVIGthe lesser the neurological sequelae and decreased LOS in thehospital. Here there was a definite delay in diagnosis anddelay in treatment based on the information provided. Thediagnosis of Guillain-Barre syndrome (GBS), is a challengeas it presents non specific symptoms and very high suspicionof index is vital in diagnosing this condition and moreimportantly treating it promptly is the key to preventing theneurological sequelae in the long run.[75] Dr Singhal continues:... Our own experience over the last 10 years here in BurwoodSpinal Unit is that every hour, every day is important inpreventing a neurological sequelae and the patients who havebeen diagnosed and treated earlier have a better neurologicaloutcome ...In Alex's case if his mum's phone call would have beenanswered appropriately and correct advice given, he wouldhave had IVIG treatment a day earlier.In general, a poor long term prognosis is directly related to theseverity of the acute episode and delay in onset of specifictreatment.Patients treated early with plasmapheresis required lessmechanical ventilation, and hospitalisation time wasdecreased.Early recognition and treatment of GBS also may beimportant in long term prognosis especially if the patient withpoor clinical prognosis signs, such as in older age, are rapidlyprogressing course and antecedent diarrhoea.[76] Dr Singhal refers to a study by Martinezen et al whichinvestigated a study to determine if early treatment of IVIG in the firstdays after onset of symptoms had a significant effect on shorteningaverage length of hospital stay.[77] They examined retrospectively records of 69 patients withGBS with group A – nine patients received no treatment of IVIG,group B – 31 patients received treatment on the sixth day and group C– 29 patients received treatment in the first five days for symptomsonset. They concluded the treatment with IVIG in the first five daysafter the onset of GBS symptoms reduces the length of time ofhospitalisation by 11 days.[78] Dr Singhal was asked what other comments he thought wouldassist and states:... The argument that the literature is only for better prognosiswithin 7 days of the diagnosis of IVIG therapy is incorrect.We see approximately 4-5 cases of GBS with severeneurological sequelae a year and a common theme in most ofthem is delay in diagnosis. The ones who were delayed earlierdo not need extensive spinal rehabilitation or ventilationsupport. I do agreed [sic] with the ACC reviewers thatliterature is not very clear on the exact timing for treatmentwhich equates to better prognosis.[79] In conclusion, Dr Singhal states:On balance the probability the delay in treatment has caused himgreater disability such that he is still requiring a wheelchair formobility, he initially was requiring a Suprapubic Catheter to managehis bladder (but has not required that since I last saw him in [sic] isvoiding normally with neurological gains) and the longer hospital stayrequired greater psychosocial input, care input and not to mention hisfamily which had experienced the highs and lows of his fight withGBS and needing ACC help to support their son.[65] It is not necessary here to go into the level of detail the District Court Judgedid in relation to the review.[66] The Judge recorded the Reviewer's reference to the report of Dr Dwyer, whohad said that a more timely treatment "may have" improved the outcome but that "itis not possible to confidently state that that is more likely".90 The Judge also notedthat the Reviewer had referred to Dr Singhal, who was supportive of Mr Reilly'streatment injury claim, and who had said that with a more timely treatment Mr Reilly'stime on ventilation "may have been shortened" and "may have meant" Mr Reillywould have been less disabled and able to walk independently or with some aid.9190 At [89].91 At [90].[67] As the Judge noted, the Reviewer had commented on Dr Singhal's use of theword "may" and had stated that it was a matter of conjecture whether treatment startedeight hours earlier would have materially altered the outcome for Mr Reilly.[68] The Judge noted that the Reviewer concluded that there was insufficientevidence to enable her to infer that Mr Reilly's condition probably would have beenbetter, let alone that he probably would not have been paralysed, but for the eight-hourdelay in the treatment of his GBS.92 For that reason, the application for review wasdismissed.93[69] The Judge then set out the relevant law, including the definition of treatmentinjury,94 and the appellant's submissions, with particular reference to the evidence ofDr Singhal, who stated that: 95On the balance of probability the cause of this autoimmune antibody mediateddamage to the nervous system would be less and the recovery from theaftermath of the disease and time on ventilation would have been shortened.This may have meant Mr Reilly would be less disabled being able to walkindependently or some other aid.[70] The Judge noted that counsel for the appellant argued that the use of the word"may" in Dr Singhal's comments did not detract from his conclusions and that the caselaw indicated robust inferences of causation could be drawn on the basis of thatevidence.96[71] The Judge recorded that counsel for the appellant had pointed out thatDr Singhal relied on his own experience treating patients,97 and his experiencestretched to over 10 years at the Specialist Spinal Unit at Burwood Hospital. Thatexperience had indicated to Dr Singhal " each hour every day is important inpreventing the neurological sequalae ".9892 At [92] (emphasis in original).93 At [93].94 At [95].95 At [111].96 At [113].97 At [122].98 At [132][72] The Judge also referred to an Australian High Court decision relied upon bythe appellant, which indicated that where medical science could not identify thebiological or pathological mechanisms by which the disease develops, such a state ofaffairs was not necessarily determinative of the existence or non-existence of a causalrelationship for the purposes of attributing legal responsibility.99[73] In reference to the appellant's reply, the Judge noted that counsel for theappellant submitted there was solid evidence in this case as to the delayed diagnosiscausing greater damage to the nervous system.100[74] The Judge noted that counsel for the appellant had summarised the appellant'sposition and had submitted the weight of the evidence suggested the delay did have amaterial effect on Mr Reilly's outcome.101 Counsel referred in this respect to theevidence of Dr St George, who said treatment within a seven day period was mosteffective, the evidence of Dr Dwyer, who said the tempo of the illness was important,and the evidence of Dr Singhal, which has been canvassed above.102 The Judgecommented that counsel for the respondent had highlighted the distinction between aninfectious disease specialist (such as Dr Dwyer), who studies the progression of thedisease, with that of Dr Singhal, who is experienced in the treatment of GBS.103Counsel for the appellant said that Dr Singhal was nevertheless somebody who wasexperienced in the treatment of the syndrome and therefore well-placed to commenton timeliness of that treatment and the correlation between the timeliness andoutcome.104[75] The Judge noted that counsel had accepted there was no specific studyregarding outcomes measurable in hours and whether or not the outcomes wereaffected if treatment was provided earlier in terms of hours.105 The Judge noted thestudies only related to whether or not the treatment is provided earlier, measurable in99 At [134], referring to Salson v McGinner. The reference in the judgment is an incorrect referenceto Seltsam Pty Ltd v McGuiness; James Hardie & Coy Pty Ltd. v McGuiness [2000] NSWCA 29at [93].100 At [210].101 At [212].102 At [212].103 At [213].104 At [213].105 At [214].days, one of which suggested earlier treatment within five days produces a betteroutcome.106[76] The Judge also dealt with the position of the respondent, and its reliance onDr Dwyer's evidence, Dr St George's evidence that he agreed with the comments andconclusions of Dr Dwyer so "there is no evidence that earlier treatment would haveimproved the outcome".107 The Judge also noted counsel's reference to Dr St George'sstatement that the Cochrane review (another piece of research) found that "treatmentwithin 7 days is the most effective" and that plasma treatment is initiated as early aspossible but up to 30 days from the onset of weakness.108[77] The Judge noted the submission of counsel that Dr Singhal's second report of26 November 2019 took the view that seven days was an arbitrary number and thatthose who were diagnosed earliest had the best outcome, particularly for those withsevere and debilitating presentation, "which is what Mr Reilly presented with."109[78] The Judge noted that counsel for the Corporation said the appellant had reliedon the evidence of Dr Singhal, who stated that damage to the nervous system wouldbe less and recovery from the aftermath of the diseases and time on ventilation wouldhave been shortened had there been an earlier intervention, but that the evidence fellwell short of identifying a physical injury. The evidence that Mr Reilly "may" havehad less severe symptoms was "speculative at most".110 Counsel went on to say thatDr Singhal's expertise was in spinal rehabilitation and he did not have expertise on theprogression and input of infections and diseases.111 Counsel therefore submitted thatthe views of Dr Dwyer, an infectious disease expert, must be preferred to that ofDr Singhal on the issue of whether delay has any input on the progress of Mr Reilly'sGBS.112 This submission appears to have been later accepted in part by counsel forthe appellant in her reply, who nevertheless maintained that while Dr Singhal was notnecessarily an expert with the relevant specialty to comment on the delay, he was,106 At [214].107 At [143].108 At [143].109 At [145].110 At [164]–[165] and [167].111 At [169].112 At [169].however, somebody who is experienced in the treatment of the syndrome andaccordingly well-placed to comment on the need for early treatment and thecorrelation between the timeliness and the outcome.113[79] The Judge went on to record the further arguments of the Corporation. Theliterature relied on by Dr Singhal only went as far as saying that delay in treatmentmay lead to a worse outcome, but did not define the period of that delay in minutes,hours, days or weeks.114 Indeed, the Judge referred to counsel's comments that theonly report mentioned by Dr Singhal to identify a delay period concluded thattreatment in the first five days after onset reduces the length of hospitalisation.115Counsel had noted that Dr Singhal had not explained how the earlier diagnosis causedmore severe GBS symptoms nor how he arrived at the conclusion that the "earlier thediagnosis [the] lesser the disability" in general terms. There was no specificsuggestion by Dr Singhal that the seven-hour delay meant that treatment wassignificantly less effective or entirely ineffective.116 In contrast, counsel said,Dr Dwyer's evidence was that earlier treatment "may" have had an influence on theappellant's residual disability and degree of independence "but it is not possible toconfidently state that this is more likely with treatment started 12 hours earlier. Thedata is just not there".117 Counsel also pointed out that Dr St George was alsodefinitive that there was "no evidence that earlier treatment would have improved theoutcome".118[80] The Judge also noted that counsel had submitted that Dr Dwyer's evidence wasthat Mr Reilly's severe and life-threatening form of campylobacterjejuni/coli associated GBS was more likely to require intensive care, ventilation andlonger hospitalisation and was more likely to result in residual disability.119Her Honour noted the submission that the literature described by Dr Singhal referredto severe or rapidly progressing illness as being a key indicator of a worse outcomeand that Mr Reilly's outcome was consistent with Dr Dwyer's description of the113 At [213].114 At [174].115 At [174].116 At [174].117 At [174] (emphasis removed).118 At [174].119 At [178].outcome for patients with campylobacter jejuni/coli associated GBS and in theliterature referred to by Dr Singhal.120[81] The Judge recorded that counsel for the Corporation concluded that Mr Reilly'scondition was caused by his underlying health, the campylobacter GBS, which was amore severe form than non-campylobacter GBS and involves a rapid onset ofsymptoms resulting in more severe disability.121 The Judge recorded this was said tosupport counsel's submission that Mr Reilly's tragic outcome was due to his severeform of the underlying condition and it was unlikely the seven-hour delay would havealtered the outcome.122[82] Having traversed the arguments of counsel, the Judge then went on to deal withthe legislation and regulations.[83] The Judge first dealt with issues surrounding the treatment injury claim.123That issue is not contested in this appeal.[84] The Judge then moved on to causation, noting that it had not been submittedthat the time spent in diagnosing or testing Mr Reilly, after he arrived atNelson Hospital before treatment was started, was the cause of any personal injury.124[85] The Judge noted the appellant's case rested on Dr Singhal's reports. The Judgereferred to his later report of 26 November 2018, in which he stated:125Could the neurological sequelae and ventilation be prevented if the diagnosiswas made earlier, the answer to this is probably not as pointed out byDr Dwyer in his opinion but could the degree of disability and time onventilation be shortened? The answer to this is yes which is clear from theliterature which I have quoted below.120 At [178].121 At [207].122 At [208].123 At [216]–[236].124 At [239].125 At [240].[86] The Judge then looked at the literature quoted by Dr Singhal.126 The Judgesaid that the article by Willson, Jacobs and van Doone referred to by Dr Singhal wasinformative with numerous references but:127 nowhere in the article does it indicate that GBS or the symptoms Dr Singhalrelies on as causing Alex's medical outcome arise from a delay ofidentification or commencement of treatment within seven and a half hours,or in fact any specific time period.[87] The Judge also noted the introductory paragraphs of the article as follows:128First Guillain-Barre syndrome is usually preceded by infection or otherimmune stimulation that induces an adherent autoimmune response targetingperipheral nerves and their spinal roots. Molecular mimicry betweenmicrobial and nerve antigens is clearly a major driving force behind thedevelopment of the disorder, at least in the case of Campylobacter jejuniinfection. However, the interplay between microbial and host factors thatdictates if and when the immune response is shifting towards unwantedautoreactivity is still not well understood. Furthermore, genetic andenvironmental factors that affect an individual's susceptibility to develop thedisease are unknown. Unwanted autoimmunity does not arise in mostindividuals (99%) exposed to an immune stimulus as a result of Guillain-Barresyndrome – associated infections such as jejuni.[88] The Judge then went on to note the reports referred to by Dr Dwyer andDr St George, and the Willson, Jacobs and van Doone article produced byDr Singhal.129 She noted Dr Dwyer also referred to two additional publications.130[89] The Judge said: 131[245] Dr Dwyer is an infectious disease specialist and as noted he states inhis report:I do not consider it at all likely that any treatment (immunoglobulinor plasmapheresis) administered that evening would have been likelyto have kept Alexander out of intensive care or off a ventilator. It mayhave had an influence on duration of disability or resumption ofmobility or degree of independence, but it is not possible to126 At [241]–[242].127 At [241].128 At [242].129 At [243].130 At [244], citing J Kaldor and B R Speed "Guillain-Barre syndrome and campylobacter jejuni: aserological study" (1984) 288 British Medical Journal 1867; and Ban Meshu and Martin J Blaser"Role of Infection Due to campylobacter jejuni in the Initiation of Guillain-Barré Syndrome"(1993) 17 Clinical Infectious Diseases 104.131 Emphasis in original.confidently state that this is more likely with treatment started 12hours earlier. The data is just not there.[246] Dr St George, in his report expresses the same view where he states:I would add that telephone triage is a difficult skill and that backup bysenior clinicians is necessary at all times. It is disappointing this wasnot available and that Ms Gannon did not comment on it.There is no evidence that earlier treatment would have improved theoutcome. The Cochrane review found only that "treatment withinseven days is the most effective" and that "plasma exchange isinitiated as early as possible but up to 30 days from the onset of theweakness". From the article by Mathew Hans, MD InpatientManagement of Guillain-Barre syndrome. Neurohospitalist 2011Apr; 12; 78/84.[247] This last article referred to is the only one which provides any medicalevidence in respect to the date for commencement of treatment.[248 It should be noted that the Cochrane review is the product of theCochrane Policy Institution (Cochrane), a British International CharitableOrganisation forum which organises medical research findings to facilitateevidence-based choices about health interventions involving healthprofessionals, patients and policy makers.It involves 53 research groups based at research institutions world-wide.[249] It is noted Cochrane have been involved in a number of researchpublications in respect to Guillain-Barre syndrome. Plasma Exchange inGuillain-Barre syndrome 2017; Multi Discipline care in Guillain-Banesyndrome October 2010; Intravenous Immunoglobulin for Guillain-Barresyndrome 2014; Treatment and Other Intravenous Relating toImmunoglobulin and Plasma Exchange for Acute Guillain-Barre Syndrome;and Cochrane View 25 June 2020, are among its publications.[90] The Judge then went on to say that she accepted that Dr Singhal had practisedmedicine for 23 years and was the present Clinical Director of the Adult RehabilitationService at Burwood Hospital, with a special interest in acute spinal cord injuries andneurological sequalae of neurological conditions such as GBS.132[91] She referred to the conclusion of Dr Singhal in his second report that on thebalance of probabilities the course of the antibody mediated damage to the nervoussystem would be less and recovery from the aftermath of the disease may be shortened,which may have meant Mr Reilly would have been less disabled, being able to walkindependently or with some aid.133 However, in relation to the questions that132 At [250].133 At [251].Dr Singhal was asked in his second report, he agreed with Dr St George in respect ofthe statement "there is no evidence that earlier treatment would have improved theoutcome".134 However, Dr Singhal alone took the view that:135There is enough evidence in the literature to say that the earlier the treatmentin the form of plasmapheresis or IVIG the less neurological sequelae anddecreased LOS in the hospital. Here there is a definite delay in diagnosis anddelay in treatment based on the information provided.The conclusion made by Dr SG for the Cochrane report shows only that"treatment within 7 days is more effective" and that "plasma exchange isinitiated as early as possible but up to 30 days from the onset of weakness".Accordingly he states that 7 days is an arbitrary number.[92] The Judge noted that Dr Singhal referred to Martinez et al, a study whichinvestigated if earlier treatment of IVIG in the first days of the onset had a significanteffect in shortening the average length of hospital stay. The study retrospectivelyexamined the records of 69 patients with GBS. Group A had nine patients whoreceived no treatment from IVIG, Group B had 31 patients who received treatmenton the sixth day and thereafter and Group C had 29 patients who received treatmentin the first five days from symptom onset.136 The results showed a mean duration ofhospital time for Group A of 47.7 days, Group B 32.4 days, and Group C 21.3 days.137Treatment with IVIG in the first five days after the onset of GBS symptoms was saidto reduce the length of hospitalisation by 11 days. However, the Judge said that didnot establish a shorter delay in diagnosis before treatment was commenced directlyimpacts the severity of the condition.138[93] The Judge said that apart from Dr Singhal's views, there was no medicalevidence before the Court that the short delay in Mr Reilly arriving at the hospital hadcontributed to a longer period in the rehabilitation centre or having ventilatorysupport.139 In fact, she noted that Dr Singhal had said that he agreed with ACCreviewers that the literature was not clear on the exact timing of treatment whichequated to better prognosis.140134 At [252].135 At [252].136 At [254].137 At [254].138 At [255].139 At [255].140 At [255].[94] The Judge accepted the submissions of the respondent that there was"insufficient material to cross the threshold of finding that on the balance ofprobabilities causation is established." The Judge accepted that "[t]he only evidencethe Court has before it as to the limited delay in treatment causing 'probable injury' to[Mr Reilly] is from Dr Singhal."141 The Judge concluded:142 I find that while Dr Singhal treated Alex at the Burwood RehabilitationUnit and has an interest in cases of this sort, he does not have the experienceor expertise of Dr Dwyer, an infection Diseases Specialist, in respect to theonset of Guillain-Barre syndrome.[258] As noted, Alex's condition was undoubtedly intensified by the factthat the evidence supports it [sic] arose from his Campylobacter infection. Asnoted by Dr Dwyer, a Campylobacter infection is commonly associated withsevere and prolonged GBS, with a greater likelihood of hospitalisation and ismore likely to require intensive care. Unfortunately, Alex falls into thiscategory.It is noted that Alex's treatment was commenced at Nelson Hospital andcontinued on the flight to Christchurch prior to him being admitted toChristchurch Hospital and was continued on his arrival at ChristchurchHospital. It is accepted his condition was severe and his recovery protracted.[95] The Judge said that she found Dr Dwyer's evidence compelling that it was "notat all likely" that treatment if administered earlier would have kept Mr Reilly out ofintensive care or off a ventilator.143 She noted Dr Dwyer had said "the data is just notthere" and there was no medical evidence or literature which supported that in allprobability Mr Reilly's condition would have improved or been shortened if he hadarrived at the hospital and/or been treated a few hours earlier.144[96] The Judge accepted that Dr Singhal had a larger role to play in Mr Reilly'srehabilitation while he was at Burwood and the reports from that hospital indicated agradual improvement. However, she said that she did not find it had been establishedthat the delay was causative of the severity of his condition.145 The Judge thereforeconcluded:[267] In respect of the treatment (or lack of treatment) being shown to haveoccurred, I find no evidence to support that delay of seven hours in presenting141 At [257].142 At [257]–[258].143 At [259].144 At [260].145 At [260].to the hospital has been causative of a treatment injury by way of Alex havingextended treatment. I find the Corporation was correct in stating "there is noevidence to suggest the delay in the diagnosis had an influence on the outcomeof Guillain-Barre syndrome".[97] The Judge went on to say that there was no medical evidence to establish thatearlier treatment would have improved the outcome, and that the best medicalevidence on this issue was that treatment within seven days was most effective andshould be initiated as early as possible within 30 days.146 She specifically noted thatthe publication referred to by Dr Singhal, did not indicate that treatment within thetimeframe suggested by Dr Singhal was essential to ensure there would be no injury.147Finally, the Judge went on to say that the further publications referred to by Dr Singhaldid not provide any additional information other than the fact that early recognitionand treatment of the syndrome was important, without providing any definitivetimeframe.148The medical evidence[98] As noted above, it is clear that the Judge in her analysis had in her mind thecorrect test of causation in that she reminded herself of the decision in Ambros as shecame to analyse causation in her judgment.149[99] There is no dispute that failure to treat or delay in treatment may give rise to atreatment injury for the purpose of cover under ACC. In this case, the Corporation hasaccepted that there was a seven to eight-hour delay and that could give rise, subject tocausation, to a claim for a treatment injury. The District Court Judge took the delayto be seven-and-a-half hours, which was within the appropriate range. The Judgemade no error in her factual findings.150[100] The Judge had carefully considered the medical evidence, including inparticular the points made by the appellant as to what did support the appellant's claim.On the basis of that evidence including the literature referred in Dr Singhal's report146 At [268].147 At [269].148 At [270].149 At [256].150 At [241].did not support the position he espoused nor prove on the balance of probabilities thatearlier treatment would have resulted in a lower level of disability. The Judgepreferred the evidence of Dr Dwyer, an infectious disease expert with expertise in theeffects of delay of treatment — such expertise having been properly accepted by theappellant's counsel.[101] After evaluating the medical evidence of both Dr Dwyer and Dr Singhal on themedical issues and the findings of the research, the Judge preferred the evidence ofDr Dwyer, as she was entitled to do, and found that the Corporation's decisiondeclining cover for the claim was correct. It cannot be said that in this case there was"no evidence to support the determination", nor that the determination was"inconsistent with and contradictory" to the evidence, such as suggested by theSupreme Court in Bryson v Three Foot Six Ltd would amount to an error of law.151[102] In the circumstances, the Judge had the evidential basis on which to make adetermination that causation was not established according to the orthodox test,correctly referred to in her judgment as a finding on the balance of probabilities.[103] As noted in Ambros, proving a causal link between a medical error and theultimate injury is frequently difficult due to scientific uncertainty over causation.152Moreover, the legal burden was on the appellant to prove causation.153 The DistrictCourt Judge properly concluded that the medical evidence did not support the standardof proof required for causation in this case. Although she identified there was someevidence produced by Dr Singhal that suggested a linkage, she was not sufficientlypersuaded by that and found this was not supported by the literature to which DrSinghal had referred. She was entitled to prefer the evidence of Dr Dwyer and Dr StGeorge and put appropriate weight on it. The Judge was entitled to come to herconclusion on legal causation based on that assessment.[104] The appellant here faced a high hurdle in asserting that the findings of theDistrict Court were erroneous in law. Intervention on a question of law on appeal is151 Bryson v Three Foot Six Ltd [2005] NZSC 34, [2005] 3 NZLR 721 at [26].152 Accident Compensation Corporation v Ambros, above n 15, at [53].153 At [63].appropriate only where the lower court has come to a conclusion for which there wasno evidence or which is inconsistent with the evidence and contradictory to it.154 Thatis not the case here.[105] The Judge made no errors. She applied the correct test for causation and herdecision is supported by the evidence.Conclusion[106] The appeal is dismissed.[107] Counsel indicated that matters relating to costs would be resolved betweenthem. Therefore, I make no determination as to costs.____________________Grice JSolicitors:John Miller Law, WellingtonClaro Law, Wellington154 See Northland Co-operative Dairy Co Ltd v Rapana [1999] 1 ERNZ 361 (CA) at [3].