ACCIDENT COMPENSATION CORPORATION v CALVER AS TRUSTEE OF THE ESTATE OF DEANNA TREVARTHEN [2021] NZCA 211

ACCIDENT COMPENSATION CORPORATION v CALVER AS TRUSTEE OF THE ESTATE OF DEANNATREVARTHEN [2021] NZCA 211 [27 May 2021]IN THE COURT OF APPEAL OF NEW ZEALANDI TE KŌTI PĪRA O AOTEAROACA592/2019[2021] NZCA 211BETWEEN ACCIDENT COMPENSATIONCORPORATIONAppellantAND ANGELA CHRISTINE CALVER ASTRUSTEE OF THE ESTATE OF DEANNATREVARTHENRespondentHearing: 25 November 2020Court: Brown, Clifford and Gilbert JJCounsel: P J Radich QC and L I van Dam for AppellantB H Woodhouse and T W R Lynskey for RespondentJudgment: 27 May 2021 at 10.30 amJUDGMENT OF THE COURTA The appeal is dismissed.B We answer the question of law submitted for determination by this Court:Does mesothelioma, not caused by work-related exposure toasbestos, amount to a "personal injury" under s 26 of the Act?Yes.C The appellant must pay the respondent costs for a standard appeal on aband A basis plus usual disbursements. We certify for second counsel.____________________________________________________________________REASONS OF THE COURT(Given by Brown J)Introduction[1] Mesothelioma is a fatal cancer caused by exposure to asbestos. Personssuffering from mesothelioma caused by work-related asbestos exposure have coverunder the Accident Compensation Act 2001 (the 2001 Act).[2] Deanna Trevarthen died from the disease at the age of 45. She maintained thather mesothelioma arose from contact as a young girl with her father whose occupationas an electrician likely involved high exposure to asbestos. Prior to her death, theAccident Compensation Corporation (ACC) declined her claim, reasoning that forcover to be available for mesothelioma it must arise as a result of work exposure.ACC's decision was upheld on review and by the District Court.1 However Mallon Jallowed the appeal in the High Court and held that Ms Trevarthen was entitled to coverunder the 2001 Act because her mesothelioma was a personal injury caused by anaccident to her.2[3] ACC has appealed to this Court. The question of law for determination is:3Does mesothelioma, not caused by a work-related exposure to asbestos,amount to a "personal injury" under s 26 of the Act?Statutory framework[4] Part 2 of the 2001 Act determines whether a person has cover under the Act.As Blanchard J proposed in Allenby v H, the best starting point is the definition ofpersonal injury in s 26(1).4 Relevant to this appeal it provides:Personal injury means—(a) the death of a person; or1 Calver v Accident Compensation Corporation [2018] NZACC 60 [District Court judgment].2 Calver v Accident Compensation Corporation [2019] NZHC 1581 [High Court judgment].3 Leave to appeal was granted by the High Court: Accident Compensation Corporation v Calver[2019] NZHC 2667.4 Allenby v H [2012] NZSC 33, [2012] 3 NZLR 425 at [56].(b) physical injuries suffered by a person, including, for example, a strainor a sprain; [5] Of particular focus in this appeal is the exclusion from the personal injurydefinition found in s 26(2):Personal injury does not include personal injury caused wholly orsubstantially by a gradual process, disease, or infection unless it is personalinjury of a kind described in section 20(2)(e) to (h).[6] This leads back to s 20. Subsection (1) lists the three prerequisites for coverfor personal injury (except mental injury caused by certain criminal acts):A person has cover for a personal injury if—(a) he or she suffers the personal injury in New Zealand on or after 1 April2002; and(b) the personal injury is any of the kinds of injuries described in section26(1)(a) or (b) or (c) or (e); and(c) the personal injury is described in any of the paragraphs in subsection(2).[7] The personal injuries described in s 20(2) are:(a) personal injury caused by an accident to the person:(b) personal injury that is treatment injury suffered by the person:(c) treatment injury in circumstances described in section 32(7):(d) personal injury that is a consequence of treatment given to the personfor another personal injury for which the person has cover:(e) personal injury caused by a work-related gradual process, disease, orinfection suffered by the person:(f) personal injury caused by a gradual process, disease, or infection thatis treatment injury suffered by the person:(g) personal injury caused by a gradual process, disease, or infectionconsequential on personal injury suffered by the person for which theperson has cover:(h) personal injury caused by a gradual process, disease, or infectionconsequential on treatment given to the person for personal injury forwhich the person has cover:(i) personal injury that is a cardiovascular or cerebrovascular episode thatis treatment injury suffered by the person:(j) personal injury that is a cardiovascular or cerebrovascular episode thatis personal injury suffered by the person to which section 28(3)applies.[8] In Allenby, noting that ss 20 and 26 each refers to the other,5 Blanchard Jdiscussed the relationship in this way:[59] Cover under s 20 is therefore available only if, first, the claimant hassuffered a personal injury and, second, that injury was caused in one of thespecified ways. As the language used in s 20 indicates, in referring to the"kinds" of injury "described" in other sections, the application of the Actdepends on judgment of likeness by reference to described categories. Inaddition, the cumulative elements of the definition indicate that the "kinds ofinjury" described in the paragraphs of s 26 are controlled by the requirementthat the injury be "described" in s 20(2).His Honour further observed that:6 the use of the term "personal injury" in para (f), and indeed throughoutsubs (2), in connection with events that would naturally be described asillnesses rather than injuries, showed that, despite s 26(1)(b), the term is beinggiven an extended meaning.[9] The phrase "personal injury caused by a work-related gradual process, disease,or infection" in s 20(2)(e) is defined in s 30:(1) Personal injury caused by a work-related gradual process,disease, or infection means a personal injury—(a) suffered by a person; and(b) caused by a gradual process, disease, or infection; and(c) caused in the circumstances described in subsection (2).(2) The circumstances are—(a) the person—(i) performs an employment task that has a particularproperty or characteristic; or(ii) is employed in an environment that has a particularproperty or characteristic; and5 Allenby v H, above n 4, at [56].6 At [76]. See also at [68].(b) the particular property or characteristic—(i) causes, or contributes to the cause of, the personalinjury; and(ii) is not found to any material extent in thenon-employment activities or environment of theperson; and(iii) may or may not be present throughout the whole of theperson's employment; and(c) the risk of suffering the personal injury—(i) is significantly greater for persons who perform theemployment task than for persons who do not performit; or(ii) is significantly greater for persons who are employed inthat type of environment than for persons who are not.Schedule 2 of the Act specifies a list of occupational diseases in respect of which s 30further provides:(3) Personal injury caused by a work-related gradual process,disease, or infection includes personal injury that is—(a) of a type described in Schedule 2; and(b) suffered by a person who is or has been in employment—(i) that involves exposure, or the prescribed level orextent of exposure, to agents, dusts, compounds,substances, radiation, or things (as the case may be)described in that schedule in relation to that type ofpersonal injury; or(ii) in an occupation, industry, or process described inthat schedule in relation to that type of personalinjury.(4) Personal injury of a type described in subsection (3) does not requirean assessment of causation under subsection (1)(b) or (c).Schedule 2 includes "[l]ung cancer or mesothelioma as caused by asbestos".7 Henceit is common ground that the 2001 Act provides cover for mesothelioma if it iswork-related.[10] Although the Judge's conclusion, that Ms Trevarthen's mesothelioma wasa personal injury caused by accident, is not an issue on this appeal, we note that thedefinition of accident in s 25(1) includes the following kinds of occurrences:(a) a specific event or a series of events, other than a gradual process,that—(i) involves the application of a force (including gravity), orresistance, external to the human body; or(ii) involves the sudden movement of the body to avoid a force(including gravity), or resistance, external to the body; or(iii) involves a twisting movement of the body;(b) the inhalation of any solid, liquid, gas, or foreign object on a specificoccasion, which kind of occurrence does not include the inhalation ofa virus, bacterium, protozoan, or fungus, unless that inhalation is theresult of the criminal act of a person other than the injured person:Relevant background[11] Ms Trevarthen began to feel unwell in the middle of 2015, having a persistentcough and suffering from chest pain, shortness of breath and weight loss. After aninitial diagnosis of bronchitis, following a chest x-ray, a CT scan and a biopsy she wasdiagnosed with malignant mesothelioma on 28 October 2015.[12] In early December 2015 Ms Trevarthen made an application to ACC forfunding. As the Mallon J explained:8Ms Trevarthen advised that her father was an electrician and, on manyoccasions when she was between the ages of four and 10, she would play athis work sites. This would include breaking particle boards and pipes whileplaying at the sites. She would also hug him every day when he got homefrom work in his work clothes.7 Clause 2.8 High Court judgment, above n 2, at [16].Ms Trevarthen's medical advice was that, given the timeframe for developingmesothelioma from when asbestos was inhaled, it was more than highly probable thatshe had contracted mesothelioma from asbestos in that manner.[13] Ms Trevarthen's claim for cover was declined by ACC on 11 January 2016 forthe reason that, because of its gradual onset, her mesothelioma was not a personalinjury caused by a specific accident on a specific occasion. Rather it was a gradualprocess disease that had not arisen from work exposure. Ms Trevarthen requestedACC reconsider her claim for cover on the basis that the disease had arisen from theinhalation of a foreign object on a specific occasion.9The decisions belowThe review decision[14] The review was directed to ACC's decision to decline the claim on the groundthat mesothelioma was not caused by a specific accident but rather developed over thecourse of time. However at the hearing ACC also advanced the argument that in thecontext of the case mesothelioma was excluded from the statutory meaning of personalinjury and was therefore excluded from cover.[15] The reviewer accepted that mesothelioma caused by asbestos inhalation wouldmeet the statutory definition of personal injury, rejecting ACC's argument that thes 26(2) exclusion of personal injuries caused wholly or substantially by a gradualprocess, disease or infection applied. He reasoned that: if the evidence establishes that the mesothelioma was caused by theinhalation of asbestos fibres then the mesothelioma must be viewed as apersonal injury, in and of itself. The cause of the mesothelioma would thennot be due to an idiopathic disease, but rather due to an external, non-diseaserelated agent.[16] The reviewer found support for this conclusion in the decision of the AccidentCompensation Appeals Authority in Stok v Accident Compensation Corporationwhich concluded that Ms Stok's mesothelioma had a specific and identifiable external9 Accident Compensation Act 2001, s 25(1)(b).cause which moved it away from an idiopathic disease.10 Accordingly Ms Stok wasfound to have suffered a personal injury by accident and was therefore entitled to coverunder the Accident Compensation Act 1982.[17] However the review was nevertheless dismissed because the reviewerconsidered that the evidence established merely a risk or possibility that the diagnosedmesothelioma was caused by asbestos inhalation. Such a risk of asbestos exposurewas insufficient to surmount the test that it was more likely than not that inhalation ofasbestos fibres had caused Ms Trevarthen's mesothelioma. For this reason ACC'sdecision was upheld.The District Court decision[18] Ms Trevarthen's executor appealed to the District Court against the reviewer'sconclusion that the mesothelioma was not shown to be caused by an accident.The ACC filed a cross-appeal directed to the finding that mesothelioma would meetthe statutory definition of a personal injury.[19] The District Court Judge considered that the reviewer was wrong to find thatmesothelioma caused by asbestos inhalation was not within the s 26(2) exclusion,ruling that it was necessary for Ms Trevarthen to demonstrate a personal injury of atype described in s 20(2)(e) to (h). In the Judge's view s 20(2)(e) was the only possiblecandidate but it was inapplicable because Ms Trevarthen's condition was not causedby a work-related gradual process.11 Stok was distinguished as having no applicationunder the 2001 Act.12[20] In any event the Judge considered that it was not established that the injury hadbeen caused by an accident involving the inhalation of a foreign object on a specificoccasion because the medical evidence available suggested that there may have beenmultiple occasions of inhalation.1310 See Stok v Accident Compensation Corporation [1995] NZAR 396 at 402. Ms Stok's exposureover an extended period of time predominantly came from her lounge and bedroom ceiling whichwas spray-coated with asbestos, but also from asbestos dust from her husband's work clothing.11 District Court judgment, above n 1, at [124]–[126].12 At [136].13 At [131].The High Court judgment[21] The Judge commenced her consideration of the availability of cover vias 20(2)(a) by considering and rejecting ACC's contention that Stok was wronglydecided. Observing that the 1982 Act excluded from the definition of personal injurydamage to the body caused exclusively by disease,14 the Judge considered that the1982 Act distinguished between diseases that arose by accident (which were covered)and diseases that were idiopathic (which were not).15[22] The Judge then turned to consider whether the Stok analysis remained validunder the 2001 Act. After reviewing aspects of the legislative history and notingrelevant changes in the drafting of the 2001 Act, the Judge identified the issue as beingwhether these changes meant s 26(2) applied to Ms Trevarthen's personal injury, inwhich event the Stok analysis would no longer apply. The Judge considered thatrelevant to that issue was whether the personal injury was the condition suffered bythe person (in this case mesothelioma) or the physical manifestations of the condition(the pain and suffering).16[23] The Judge proceeded to consider the majority and minority judgments inAllenby,17 a case considering whether a pregnancy following a failed sterilisation wasa personal injury caused by medical misadventure covered by the 2001 Act. The Judgestated:18[73] As I see it, the difference between the majority reasoning and thereasoning of Elias CJ is how they view what is the personal injury and whatis seen as the cause of that injury. The majority considered pregnancy to bean injury because it has physical impacts on the body which progress.The pregnancy was caused by medical misadventure (the failed sterilisation).Elias CJ considered the physical impacts of the pregnancy to be the personalinjury. Because pregnancy is a gradual process, those physical impacts, afterthe initial impregnation, were caused wholly or substantially by a gradualprocess.14 See the definition of "personal injury by accident" in s 2(1) of the Accident Compensation Act1982 at (b)(ii).15 High Court judgment, above n 2, at [50].16 At [63].17 Allenby v H, above n 4. The majority decision comprised Blanchard, McGrath andWilliam Young JJ, with Tipping J delivering a separate concurring judgment. Elias CJ dissented.18 High Court judgment, above n 2.[74] The difference in view between the majority and minority arosebecause the personal injury had progressive physical impacts. If it is thephysical manifestations of the injury that constitute the "personal injury", thenwhat has caused the final stage of the injury (and whether that cause is agradual process) might be something different from what caused the firstphysical manifestation of the injury. The majority approach took the injury asa whole (the pregnancy) and asked what caused it (the medical misadventure).[24] The Judge concluded that mesothelioma is a personal injury under s 26(1) andthat s 26(2) does not apply, reasoning as follows:[75] The majority view is the one that binds this court. The personal injuryis defined by the condition as a whole that a person has. The conditionqualifies as a personal injury because it has physical impacts. Just as a sprainqualifies as a personal injury because it has physical impacts that causes painand suffering, so too does pregnancy, and mesothelioma, because of theirphysical impacts on the body. As the Lord High Chancellor Earl of Halsburyput it, "when some affection of our physical frame is in any way induced byaccident, we must be on our guard that we are not misled by medical phrases".His example is someone sustaining a cut to their skin which sets up tetanus.As he explains, "tetanus is a disease; but would anybody contend that therewas not an accident causing damage"? Another example, as given to ACC byDr Monigatti in April 2016, is lead poisoning in a child who ate paint scrapingson a specific occasion.[76] This does not mean all diseases are covered. They still need to comewithin s 20(2). Idiopathic diseases, that is those that develop in a person froman unknown cause, and that are not consequential on covered events, remainoutside the scope of the Act. As the Authority said in Stok, for example, canceris "something which occurs generally without explanation and in very fewcases can it be directly related to any external cause". Idiopathic diseases willgenerally be excluded because they are caused by a gradual (internal) processrather than a known external cause.[77] In my view this approach is not inconsistent with the Act's scheme toprovide cover for work-related gradual process, disease or infection. Coverfor this can, in theory, arise under s 26(2)(e) through two routes: as personalinjury under s 26(1) which is not personal injury under s 26(2); or as personalinjury under s 26(1) which is also personal injury under s 26(2). Which ofthese routes does not matter in a work-related personal injury because thes 30(1) definition essentially replicates the s 26(2) requirement for thepersonal injury to be caused by a gradual process, disease or infection.This allows work injuries to be covered where they might not have qualifiedas an accident at common law or under workers' compensation legislation.Further, a number of occupational diseases are expressly within s 20(2)(e) bytheir inclusion in Schedule 2. Mesothelioma is one of those. Including somediseases and infections in Schedule 2 (and thereby providing clarity in suchclaims) does not necessarily show that Parliament intended that they could notbe covered outside the work context on other grounds.[78] Nor does this approach deprive s 26(2) of meaning. For example,degeneration of the back may be wholly or substantially caused by a gradualprocess (if there is no known external cause that triggered this, such as aninitial accident). Heart disease may be wholly or substantially caused by agradual (internal) process. Some gradual processes, diseases or infectionsmay go on to cause other diseases. In these cases, the personal injury forwhich the person is seeking cover, will only have cover if it is of a kinddescribed in s 20(2)(e) to (h).(Footnotes omitted.)[25] A new argument was advanced in support of the appeal to the High Court thatcover was alternatively available under s 20(2)(g), which allows cover for gradualprocesses, diseases or infections consequential on a personal injury for which a personhas cover. ACC responded that it was prejudiced in having to address this argumentfor the first time on appeal, noting that it had not had the opportunity of presentingevidence that would be relevant to this ground.[26] While considering that the conclusion under s 20(2)(a) meant that it wasunnecessary to consider the new argument, the Judge nevertheless thought it wasuseful to determine if a different conclusion would be reached through s 20(2)(g) as away of testing the analysis under the primary ground. On this issue, the Judge foundthat if there was initial damage from inhaling the asbestos fibres that constituted apersonal injury covered by the legislation, the second personal injury (the developmentof mesothelioma) would be consequential of the first injury.19 She concluded:20I do not reach a final view on whether there would be cover under s 20(2)(g).It is not the way it was argued in the District Court, or earlier, and it was notthe subject of leave to appeal. However, the analysis as far as it goes, suggeststhere may not be any difference in outcome whether s 26(2) applies or not.Under either basis for cover, the critical issue is whether there has been an"accident" as defined in s 25. In my view, there has been.The issues[27] The issue agreed by the parties was simply the question of law the subject ofthe grant of leave. The question is one of statutory interpretation concerning themeaning and effect of s 26(2). Is it effective to confine cover under the 2001 Act inrespect of diseases to the personal injuries described in s 20(2)(e) to (h), as ACCcontends? Or is s 26(2) to be construed as not extending to the scenario wherein the19 At [137].20 At [138].disease or infection is itself triggered by an accident (such as the inhalation describedin s 25(1)(b)), with the consequence that cover would be available via s 20(2)(a)?ACC's submissions[28] ACC contends that s 26(2) is an expression of the general policy of the accidentcompensation regime to exclude disease from cover except in specified circumstances.Claimants who have a disease have cover only if they fall within those circumstancesdescribed in s 20(2)(e) to (h). Where the disease has a known, external cause, the onlypathway to cover is under s 20(2)(g).[29] ACC draws a distinction between a disease and its effects. In the context ofs 26(2) it contends that "personal injury" is the specific harm to the claimant's bodyfor which cover is sought, not the label given to the claimant's underlying condition.In other words, the "personal injury" is the physical manifestation of the disease, notthe disease itself. Ms Trevarthen met the requirements for s 26(1)(a) and (b) as shesustained serious physical injuries (including pleural effusion and tumours). However,because those physical injuries and her death resulted from the disease mesothelioma,they were excluded from the definition of personal injury by reason of s 26(2).[30] In support of this argument, ACC submitted:(a) Its interpretation is consistent with the definition of personal injury ins 26(1) which is defined by reference to specific examples of bodilydamage, namely a strain, a sprain and death.(b) Its interpretation is also consistent with the way in which personalinjury has been further articulated by the courts as requiring a tangibleor appreciable harm or damage to the body.21(c) The description of personal injury by Elias CJ in Allenby supportsACC's analysis. The Chief Justice distinguished between the types of21 Citing Teen v Accident Compensation Corporation DC Wellington 244/2002, 3 September 2002at [13]; Falwasser v Attorney General [2010] NZAR 445 (HC) at [90]; Allenby v H, above n 4, at[56]; and Murray v Accident Compensation Corporation [2013] NZHC 2967 at [60].personal injury for which a claimant could seek cover: theimpregnation/conception itself or the "physical consequences broughtabout by the process of pregnancy".22(d) The integrity of the statutory scheme would be compromised materiallyif personal injury was defined as the disease itself.23[31] Having regard to the scheme as a whole, ACC submits that non work-relatedmesothelioma can attract cover under the Act only through the application ofs 20(2)(g). Hence ACC invited the Court to answer the question of law in thefollowing qualified way: the physical manifestations of mesothelioma, not caused bywork-related exposure to asbestos, can amount to a "personal injury" under s 26 of the2001 Act only through s 20(2)(g).Respondent's submissions[32] Ms Woodhouse for the respondent submitted that, unlike diseases whichrequire cumulative exposure and would not attract cover under the legislation,mesothelioma has a single, uniform trigger and is "indivisible". Such unique featuresallow mesothelioma to be conceptualised as personal injury caused by an accident.[33] On the issue of the appropriate pathway to cover, Ms Woodhouse submittedthat the issue for determination (whether mesothelioma is a personal injury caused byaccident (s 20(2)(a)) or one caused wholly or substantially by a disease and thusexcluded unless captured by s 20(2)(e) to (h)) engages the same distinction which theSupreme Court grappled with in Allenby. While acknowledging that Allenby was notbinding on the High Court or on this Court, she submitted there are close analogies tobe drawn with the Allenby reasoning and highlighted "two crucial points":3.8 First, it must be understood that the Court in Allenby was interpreting"physical injuries" broadly, not "personal injury" as whole. That setsup the availability of externally caused gradual processes (or, byextension, diseases) because a broad interpretation of physical injuriesin s 26 leads to the enquiry as to what caused those injuries(to determine whether they satisfy s 20). It is here that almost all22 Allenby v H, above n 4, at [25].23 The interpretation of a provision must be interpreted in light of the statute as a whole: Ross CarterBurrows and Carter: Statute Law in New Zealand (5th ed, LexisNexis, Wellington, 2015) at 258.gradual processes, diseases or infections will be excluded, and theintegrity of the scheme thereby protected.3.9 Secondly, and following on from this, it must always be recalled thatrequiring an approved s 20(2) pathway for the injury acts as asignificant filter on coverable injuries. However, it is a filter that doesnot capture pregnancy caused by medical misadventure ormesothelioma caused by an accident, because causation is not at issuein either situation.(Footnotes omitted.)[34] Describing the language of s 26(2) as cumbersome, Ms Woodhouse viewedMallon J's analysis that mesothelioma fell outside s 26(2) as resting on the footing thatit is a physical injury, expansively viewed, caused wholly by an external agent, citingthe observation of Elias CJ in Allenby:24[18] The meaning of "personal injury caused by medical misadventure"covers physical impact upon the person, expansively viewed. As Blanchard Jsays, it has a statutory meaning. An infection is not in general speech referredto as a personal injury. And yet the terms of [s 32(7)] make it clear that it isso regarded for the purposes of personal injury caused by medicalmisadventure. It must be interpreted in the light of the purposes of the Actwhich are concerned with establishing entitlements for impairment,rehabilitation, and treatment.[35] Ms Woodhouse submitted that the focus is on the condition as a whole andimportantly its cause because this reflects the concerns of the 2001 Act withestablishing entitlements for impairment, rehabilitation and treatment. Understoodfrom that angle it was submitted that the real utility of s 26(2) is as a filter in respectof causation, being a refinement on the original exclusion of damage causedexclusively by a disease. She contended that recognising a pathway to cover unders 20(2) when causation is not in issue (as in both pregnancy and mesothelioma) doesnot render the consequential paragraphs in s 20(2) otiose (as ACC maintains). AsMs Woodhouse put it, legal and factual causation remain significant filters in s 26 andthe additional routes to cover under s 20(2) can then be understood as expansive, notreductive.25[36] In the event that this Court were to accept ACC's submission that cover is onlyavailable under s 20(2)(g), then Ms Woodhouse submitted that the Court has the24 Allenby v H, above n 4.25 Citing Blanchard J in Allenby v H, above n 4, at [76].evidence necessary to decide the case on the basis of that provision and she invited usto do so.Analysis[37] ACC accepts that the accident compensation scheme has always made adistinction between diseases, providing cover for some and not others. However itcontends that the parameters of cover for non work-related disease have changed overtime. It says that there is no longer a simple distinction between idiopathic diseaseand disease with an external/accidental cause. As noted above, ACC's position is thatunder the current legislation diseases with an external cause are covered only if theyfall within s 20(2)(g).[38] We discern that there are two, seemingly interrelated, limbs to ACC'sargument:(a) First, the endpoint of the statutory evolution is that cover is onlyavailable for non work-related disease in the circumstances stated ins 20(2)(g).(b) Second, in reliance on a distinction drawn between personal injury anddisease, even where a disease is attributable to an external cause, onlythe disease is the cause of injury (namely tangible harm to the body),not the external cause.[39] In order to evaluate the first limb of the argument it will be convenient to beginby tracing the path of the legislative evolution.The 1972 and 1982 Acts[40] The original purpose of the scheme was to provide cover for personal injurycaused by an accident to the claimant.26 The Accident Compensation Act 1972 asoriginally enacted contained a non-exhaustive definition of "personal injury byaccident" which included incapacity resulting from an occupational disease to the26 Allenby v H, above n 4, at [60].extent that cover extended in respect of the disease under ss 65 to 68 of that Act.27Section 67 made provision for compensation for diseases arising out of employment.However s 67(8) recorded that nothing in that section affected the right of any personto receive compensation in respect of disease if the disease was a personal injury byaccident within the meaning of the statute.[41] In 1974 a more detailed definition was substituted as follows:28Personal injury by accident—(a) Includes—(i) The physical and mental consequences of any such injury orof the accident:(ii) Medical, surgical, dental, or first aid misadventure:(iii) Incapacity resulting from an occupational disease or industrialdeafness to the extent that cover extends in respect of thedisease or industrial deafness under sections 65 to 68 of thisAct:(b) Except as provided in the last preceding paragraph, does not include—(i) Damage to the body or mind caused by a cardio-vascular orcerebro-vascular episode unless the episode is the result ofeffort, strain, or stress that is abnormal, excessive, or unusualfor the person suffering it, and the effort, strain, or stress arisesout of and in the course of the employment of that person asan employee:(ii) Damage to the body or mind caused exclusively by disease,infection, or the ageing process.That definition was replicated in the 1982 Act, the legislation under which Stok wasdecided.27 This is found in the interpretation provision in s 2(1). Pursuant to an amendment in 1973, allpersons had cover in respect of personal injury by accident in New Zealand: AccidentCompensation Amendment (No 2) Act 1973, s 4.28 By s 2(1) of the Accident Compensation Amendment Act 1974.The 1992 Act[42] There was no such composite definition in the Accident Rehabilitation andCompensation Insurance Act 1992. A definition of "accident" was introduced, similarto that in the current s 25(1), which included in the first limb an exclusion in respectof "any gradual process". "Personal injury" was stated to have the meaning assignedto it by ss 4 and 8.29 Section 4 provided the definition of personal injuries under theAct:4. Definition of "personal injury"—(1) For the purposes of this Act,"personal injury" means the death of, or physical injuries to, a person, and anymental injury suffered by that person which is an outcome of those physicalinjuries to that person, and has the extended meaning assigned to it bysection 8(3) of this Act.(2) For the purposes of this Act, no cardio-vascular or cerebro-vascularepisode shall be regarded as personal injury unless—(a) It is a result of medical misadventure; or(b) It is a work injury by virtue of section 6(1) of this Act.[43] The availability of cover was specified in s 8, and exclusions were then listedin s 10:8. Cover for personal injury occurring in New Zealand(2) Cover under this Act shall extend to personal injury which—(a) Is caused by an accident to the person concerned; or(b) Is caused by gradual process, disease, or infection arising outof and in the course of employment as defined in section 7 orsection 11 of this Act; or(c) Is medical misadventure as defined in section 5 of this Act; or(d) Is a consequence of treatment for personal injury.3029 See interpretation provision in s 3.30 The phrase "covered by this Act" was added to para (d) by s 5(1) of the Accident Rehabilitationand Compensation Insurance Amendment Act (No 2) 1993.10. General exclusions from cover—(1) For the avoidance of doubt, itis hereby declared that personal injury caused wholly or substantially bygradual process, disease, or infection is not covered by this Act unless it is—(a) Personal injury caused by gradual process, disease, orinfection arising out of and in the course of employment asdefined in section 7 or section 11 of this Act; or(b) Personal injury that is medical misadventure; or(c) A consequence of personal injury or treatment for personalinjury.31[44] The new phrase "gradual process, disease, or infection", which appeared inboth ss 8 and 10, replaced the phrase "disease, infection, or the ageing process" in theformer definition of personal injury by accident.32 An exclusion in respect of theageing process was separately addressed in s 10(2)(a).[45] The implications of the 1992 changes are summarised by Todd on Torts in thisway:33The bases for cover were similar to those laid down in the earlier Acts but theirscope was precisely, and in some respects far more restrictively, defined. Sothere was cover for personal injury caused by an accident, byemployment-related disease or infection, by medical misadventure and bytreatment for personal injury, and also for mental or nervous shock sufferedby the victims of certain specified sexual offences. However, whereasformerly these categories all fell within the broad concept of "personal injuryby accident" (which had only a non-inclusive definition), they were nowtreated as separate categories and made subject to a series of detaileddefinitions. Judicial discretion in determining their limits was largelyremoved.[46] The submission for ACC emphasised that in 1992 cover for disease changed intwo respects. First, the threshold for causation of damage to the body by disease waslowered from "exclusively" in the 1972 and 1982 Acts to "wholly or substantially".As ACC put it:In other words, the legislation contemplated that there could be another causalfactor, but if disease was the substantial cause of the damage, it was primafacie excluded from cover.31 The phrase "covered by this Act" was added to para (c) by s 7 of the Accident Rehabilitation andCompensation Insurance Amendment Act (No 2) 1993.32 At [41] above.33 Stephen Todd (ed) Todd on Torts (8th ed, Thomson Reuters, Wellington, 2019) at [2.2.05].Secondly the addition of a definition of personal injury in finite terms was said toreflect a deliberate policy shift as explained in a report prepared by the Minister ofLabour which stated:34 [S]ince the inception of the scheme, a series of statutory, administrative,and judicial decisions has resulted in an extension of the scheme's boundariesbeyond what was originally intended in respect of "injuries" arising from an"accident"; and this has resulted in substantial cost increases.Legislation will be introduced in this session of Parliament and will be enactedto take effect from 1 July 1992. The changes to the scheme will ensure thatfair and equitable compensation and rehabilitation remains available to thosewho suffer injury as a result of genuine accident; it will ensure that the costsof the scheme are distributed fairly amongst users and that the costs are ableto be met by users; it will ensure that the scheme remains viable and does notjeopardise New Zealand's economic recovery.[47] We simply note at this juncture that, even following those changes, coverwould have remained available via s 8(2)(a) for a non work-related personal injurycaused by an accident and not caused wholly or substantially by a disease or infection.The 1998 Act[48] While the genesis of the current s 26(2) can be identified in s 10 of the 1992Act,35 the precursor first appeared in the Accident Insurance Act 1998. The significantdrafting change for present purposes was that the mechanism for the exclusion of coverin respect of a gradual process, disease or infection was incorporated into the provisiondefining personal injury:29. "Personal injury"—(1) "Personal injury" means—(a) The death of an insured; or(b) Physical injuries suffered by an insured, including, for example, astrain or sprain; or(c) Mental injury suffered by an insured because of physical injuriessuffered by the insured; or(d) Mental injury suffered by an insured in the circumstances describedin section 40.34 W F Birch Accident Compensation: A Fairer Scheme (30 July 1991) at 8–9.35 At [43] above.(2) "Personal injury" does not include personal injury caused wholly orsubstantially by a gradual process, disease, or infection unless it is personalinjury of a kind described in section 39(2)(d), (e), (f), or (g).[49] The circumstances in which cover was provided were detailed in s 39:39. Cover for personal injury suffered in New Zealand (except mentalinjury caused by certain criminal acts)—(1) An insured has cover for apersonal injury if—(a) He or she suffers the personal injury in New Zealand on or after 1 July1999; and(b) The personal injury is any of the kinds of injuries described in section29(1)(a), (b) or (c); and(c) The personal injury is described in any of the paragraphs insubsection (2).(2) Subsection (1) (c) applies to—(a) Personal injury caused by an accident to the insured; or(b) Personal injury caused by medical misadventure suffered by theinsured; or(c) Personal injury caused by treatment given to the insured for personalinjury for which the insured has cover; or(d) Personal injury caused by a work-related gradual process, disease, orinfection suffered by the insured; or(e) Personal injury caused by a gradual process, disease, or infection thatis personal injury caused by medical misadventure suffered by theinsured; or(f) Personal injury caused by a gradual process, disease, or infectionconsequential on personal injury suffered by the insured for which theinsured has cover; or(g) Personal injury caused by a gradual process, disease, or infectionconsequential on treatment given to the insured for personal injury forwhich the insured has cover; or(h) Personal injury that is a cardio-vascular or cerebro-vascular episodethat is personal injury caused by medical misadventure suffered by theinsured; or(i) Personal injury that is a cardio-vascular or cerebro-vascular episodethat is a personal injury suffered by the insured to which section 32(2)applies.[50] This then was the point in the legislative development that thecross-referencing between the provisions occurred as described by Blanchard J.36[51] ACC submitted that the policy shift apparent in the 1992 Act was furtherentrenched under the 1998 Act:The 1998 Act, in terms almost identical to the current Act, repeated the generalpolicy that personal injury caused wholly or substantially by disease was notcovered, but provided an exception for disease caused by an external factorwhere the disease was "consequential on personal injury suffered by theinsured for which the insured has cover".(Footnotes omitted.)The 2001 Act[52] Section 39(1) and (2) reappeared as s 20(1) and (2) of the 2001 Act.37 Howeversubs 20(2) was amended to its current form in 2005 by the reform which replacedmedical misadventure with treatment injury.38 Section 26 of the 2001 Act was thebroad equivalent of s 29 of the 1998 Act.[53] With reference to the question of law we are required to address, there were nomaterial differences between the pair of cross-referencing provisions in the 1998 and2001 Acts.The first limb of ACC's argument[54] As earlier noted,39 ACC argues that the parameters of cover for nonwork-related disease have changed over time such that there is no longer a simpledistinction between idiopathic disease and disease with an external/accidental cause.It says now the only pathway for cover for non work-related diseases is s 20(2)(g).36 At [8] above.37 The original name of the 2001 Act was the Injury Prevention, Rehabilitation and CompensationAct 2001.38 Injury Prevention, Rehabilitation, and Compensation Amendment Act (No 2) 2005, s 7.39 At [37] above.[55] The relevant changes are said to have occurred in 1992 and 1998. As ACCput it:69. It is evident that the parameters of cover for disease haveprogressively narrowed. Under the 1972 and 1982 Acts, the damagehad to amount to a physical consequence of an accident, with"accident" interpreted by the courts in very broad terms. The 1992Act provided cover if the damage from the disease was a consequenceof personal injury. Since 1998, cover for disease with an externalcause is only available where the disease is "consequential onpersonal injury suffered by the person for which the person hascover".[56] With reference to the statement (in the third sentence) as to the implications ofs 10(1)(c) of the 1992 Act, that exception only arose if the personal injury was causedwholly or substantially by disease. As we noted in the course of our historical review,cover remained available for a personal injury which was caused by an accident andnot caused wholly or substantially by a disease.40[57] The second claimed legislative development upon which we infer ACCprimarily relies (in the fourth sentence in the above extract) is that since 1998 coverfor disease having an external cause is only available where the disease is of the naturedescribed (currently) in s 20(2)(g), namely: consequential on personal injury suffered by the person for which theperson has cover.[58] Precisely why s 20(2)(g) should have the effect of excluding cover otherwiseavailable via s 20(2)(a) is not made clear. We infer that the reasoning involves somevariant of the maxim that the explicit mention of one thing implies the exclusion ofanother.41 However in our view the presence within s 20(2) of the particularmanifestation of personal injury described in (g) simply reflects the outcome of a longlegislative evolution and in particular the changes in the drafting mechanisms adopted.[59] To recapitulate, the changes in 1992 and 1998 comprised:40 At [47] above.41 Expressio unius est exclusio alterius.(i) in the 1992 Act the exclusion from cover of non work-related personalinjury caused wholly or substantially by disease unless it was a medicalmisadventure (s 10(1)(b)) or, more relevantly, a consequence ofpersonal injury or treatment for personal injury (s 10(1)(c));(ii) the amendment in 1993 to add to s 10(1)(c) the phrase "covered by thisAct";42 and(iii) the adoption in the 1998 Act of the drafting mechanism of including inthe definition of personal injury the general exclusion for gradualprocesses, diseases or infections (s 29) and listing in the cover provisionthe various exceptions to the exclusion from cover (s 39), both of whichwere previously contained in s 10 of the 1992 Act.[60] We are unable to discern from the tortuous43 drafting history a legislativeintention44 whereby the instances of personal injury described in s 20(2)(e) to (h)should be construed so as to read down, or indeed impliedly repeal, other instances ofpersonal injury within s 20(2).[61] We say impliedly repeal for this reason. If there can only be cover for diseaseif one of the grounds in s 20(2)(e) to (h) is applicable, then presumably the samelimitation must apply to both gradual process and infection. If so, then what is the fateof s 20(2)(c) which relates to treatment injury in the circumstances described in s 32(7)which states:If a person (person A) suffers an infection that is a treatment injury, cover forthat personal injury extends to—(a) person A's spouse or partner, if person A has passed the infection ondirectly to the spouse or partner:(b) person A's child, if person A has passed the infection on directly to thechild:(c) any other third party, if person A has passed the infection on directionto that third party:42 Above n 31.43 Allenby v H, above n 4, at [68].44 Commerce Commission v Fonterra Co-operative Group Ltd [2007] NZSC 36, [2007] 3 NZLR767 at [22].(d) person A's child or any other third party, if—(i) person A has passed the infection directly to his or her spouseor partner; and(ii) person A's spouse or partner has then passed the infectiondirectly to the child or third party.[62] Criticising the judgment below, ACC submits:70. The net effect of Her Honour's decision is that disease is covered, notonly if one of the grounds in s 20(2)(e) – (h) is invoked (which is whats 26(2) expressly contemplates) but, additionally, if the situation fallswithin s 20(2)(a).71. The statutory scheme is prescriptive. It was not open to Mallon J togo beyond the clear terms of s 26(2) to introduce a new category ofcover for disease based simply on the existence of anexternal/accidental factor.[63] Logically the same criticism should apply to the recognition of cover forinfection under s 20(2)(c). However Parliament cannot have intended to includess 20(2)(c) and 32(7) covering transmission of infection to others in the knowledgethat it was then to be nullified by the combined effect of ss 26(2) and 20(2)(e) to (h).[64] The criticism of the Judge for introducing a new or additional category of coverfor disease is misconceived. The pathways to cover are specified in s 20(2). There isnothing in the 2001 Act, and certainly not in s 26(2), which states that personal injuryassociated with a disease or infection may only attract cover via s 20(2)(e) to (h)irrespective of the cause or origin of the disease.[65] ACC then mounts an additional argument founded on the need to justify theexistence of s 20(2)(g):Section 20(2)(g) provides a contextual clue that diseases with a known causeare captured by s 26(2). This is because [s] 20(2)(g), which is triggered by theapplication of s 26(2), is dependent on, or presupposes, there having been acause to the disease. The phrase "caused wholly or substantially" in s 26(2)has to be interpreted in a way that does not render s 20(2)(g) obsolete.[66] The argument is as unattractive as it is unsound. We agree withMs Woodhouse's submission that the various routes to cover in s 20(2) should beviewed as expansive, not reductive. Sometimes the additional dimension provided bya separate statutory provision will not be easy to identify, at least in the abstract.For example we note that in his dissenting judgment in Accident CompensationCorporation v D William Young P saw little difference between s 20(2)(b) and (f).45[67] In our view it is not necessary for the meaning of s 26(2) to be constrained ordistorted on account of the existence of s 20(2)(g). Section 26(2) simply envisagesthat some personal injuries will be caused wholly or substantially by disease orinfection and others will not.46 Those in the latter category are unaffected by thequalification in s 26(2) which cross-references to s 20(2). Neither the fact of s 20(2)(g)nor its terms are of any consequence for cases in that latter category.The second limb of ACC's argument[68] The Judge made reference47 to the Lord Chancellor's example of an injury inBrintons Ltd v Turvey:48Suppose in this case a tack or some poisoned substance had cut the skin andset up tetanus. Tetanus is a disease; but would anybody contend that there wasnot an accident causing damage?[69] In that example the originating event (and, we would say, the operative causeof the damage to the worker) was the accident whereby the worker's skin was cut. Thecut caused tetanus and hence the worker suffered from that disease. In suchcircumstances, where the cut was the operative cause, could it fairly be said thats 26(2) applied to exclude cover?[70] But it is at this point that ACC's further argument is deployed, to the effect that,while the accident may have caused the disease (or infection), it is the disease(or infection) that caused the injury (and not the accident). In response to theLord Chancellor's rhetorical question, ACC would raise its hand.45 Accident Compensation Corporation v D [2008] NZCA 576 at [75].46 The omission of reference to gradual process reflects the exclusion of gradual process from thefirst definition of accident in s 25(1)(a).47 High Court judgment, above n 2, at [75]: see [25] above. It was also noted in Stok v AccidentCompensation Corporation, above n 10, at 403–404.48 Brintons Ltd v Turvey [1905] AC 230 (HL) at 233.[71] In short ACC submitted:(a) Personal injury is tangible harm that something causes to the body.(b) The inhalation of asbestos caused the disease (mesothelioma).(c) The disease "in turn" caused the personal injury (pleural effusion,tumours and death). But the personal injury is not the disease.[72] The submission may be diagrammatically portrayed in this way:[external cause] [disease] [tangible harm to body]s 26(2) applies[73] The Judge rejected that submission. She did so for the reason she consideredherself bound to follow the majority view in Allenby.49 However we agree withMs Woodhouse's acknowledgment that Allenby was not binding on the Judge, norindeed on this Court. Allenby concerned a failed sterilisation and the application ofthe statutory provisions relating to medical misadventure. Issues raised includedwhether pregnancy, a gradual process, amounted to a personal injury and thecircumstances in which cover would be available.[74] Nevertheless, we consider that the Judge's conclusion was correct for thefurther reasons advanced in her judgment at [75].50 There is no advantage inparaphrasing them. However in particular we agree that personal injury is defined bythe person's condition as a whole. In our view it is artificial to draw a distinctionbetween being inflicted with a disease and experiencing the physical manifestationsof the disease and then, by reference to such a distinction, to nominate the disease (asdistinct from its external cause) as the cause of the personal injury. We cannot discernthe intentional drawing of such a distinction in the legislation. Certainly it could notbe said to derive from the confusing structure of s 26(2) which deploys the phrase"personal injury" three times.49 High Court judgment, above n 2, at [75].50 At [24] above.[75] We also agree with the Judge's analysis at [76] that such conclusion does notmean all diseases are covered and with her view at [77] that such an approach is notinconsistent with the statutory scheme to provide cover for work-related gradualprocess, disease or infection.51Conclusion[76] Ms Trevarthen suffered personal injury in terms of s 26(1)(a) and (b), subjectto it being excluded under s 26(2). We have found that the personal injury was notexcluded under s 26(2) because it was not caused wholly or substantially by a gradualprocess, disease or infection. Rather, the personal injury was caused by an accident tothe person in terms of s 20(2)(a), namely the accidental inhalation of asbestos fibres.[77] Consequently, our answer to the question of law, does mesothelioma notcaused by a work-related exposure to asbestos amount to a "personal injury" under s26 of the Act, is yes.[78] Even if we had answered the question in the negative, we would not haveentertained Ms Woodhouse's request to consider the s 20(2)(g) argument. To do sowould have necessitated making factual findings which would not be appropriate inan appeal confined to questions of law.52Result[79] The appeal is dismissed.[80] The appellant must pay the respondent costs for a standard appeal on a band Abasis plus usual disbursements. We certify for second counsel.Solicitors:Accident Compensation Corporation, Wellington for AppellantJohn Miller Law, Wellington for Respondent51 At [25] above.52 Under s 163 of the 2001 Act.