AAI Limited v State Insurance Regulatory Authority of New South Wales

Solicitors: Moray & Agnew (Applicant) Crown Solicitor (First and Second Respondents) Brydens Lawyers Pty Limited (Third Respondent) File Number(s): 2015/230961 Publication restriction: Nil Decision under appeal Court or tribunal: Supreme Court of New South Wales Jurisdiction: Common Law Citation: [2015] NSWSC 912 Date of Decision: 10 July 2015 Before: Button J File Number(s): 2014/76836

[Note: The Uniform Civil Procedure Rules 2005 provide (Rule 36.11) that unless the Court otherwise orders, a judgment or order is taken to be entered when it is recorded in the Court's computerised court record system. Setting aside and variation of judgments or orders is dealt with by Rules 36.15, 36.16, 36.17 and 36.18. Parties should in particular note the time limit of fourteen days in Rule 36.16.] HEADNOTE [This headnote is not to be read as part of the Judgment] The third respondent, Ms Vanessa Sproule, lodged an insurance claim with AAI Limited trading as AAMI (AAMI) seeking to recover damages in respect of injuries she said she suffered during a motor vehicle accident on 5 July 2009 involving the driving of a vehicle by her ex-partner, Mr Judd Ball. AAMI was Mr Ball's motor vehicle insurer. A dispute arose as to the extent to which Ms Sproule's permanent impairment was caused by the incident. AAMI contended the incident in which Ms Sproule was injured involved five phases, only some of which involved a motor vehicle, and others of which involved Mr Ball physically assaulting Ms Sproule. A medical assessor appointed by the State Insurance Regulatory Authority of New South Wales (Authority) determined that Ms Sproule had a whole person impairment of 14 per cent. AAMI sought a review of this assessment pursuant to s 63 of the Motor Accidents Compensation Act 1999 (NSW) (MAC Act). The review application was rejected by the Proper Officer of the Authority's Medical Assessment Service. AAMI sought judicial review of the Proper Officer's decision. The primary judge found that the Proper Officer's determination did not demonstrate jurisdictional or non-jurisdictional error and dismissed the judicial review application. AAMI sought leave to appeal. Its principal contention on appeal was that the MAC Act, in particular, s 58(1)(d) and s 131, required a medical assessor to make a determination as to, or to characterise, what elements of an incident involving a motor vehicle during which a person was injured was a "motor accident" within the meaning of s 3 of the MAC Act. It argued that conclusion followed from the proper construction of the MAC Act and a line of authority, principally Motor Accidents Authority of NSW v Mills (2010) 78 NSWLR 125; [2010] NSWCA 82. Held, granting leave to appeal and dismissing the appeal: per McColl JA and Simpson JA (Macfarlan JA agreeing) (1) On its proper construction the MAC Act does not require a medical assessor to make a determination as to what elements of an incident involving a motor vehicle during which a person was injured was a "motor accident" within the meaning of s 3 of the MAC Act: [7], [123], [159], [197]. Project Blue Sky Inc v Australian Broadcasting Authority (1998) 194 CLR 355; [1998] HCA 28; Alcan (NT) Alumina Pty Ltd v Cmr of Territory Revenue (Northern Territory) (2009) 239 CLR 27; [2009] HCA 41; Military Rehabilitation and Compensation Commission v May (2016) 90 ALJR 626; [2016] HCA; Smalley v Motor Accident Authority of New South Wales (2013) 85 NSWLR 580; [2013] NSWCA 318 applied. per McColl JA (Macfarlan JA agreeing, Simpson JA not deciding) (2) Motor Accidents Authority of NSW v Mills is not authority for any larger proposition than that the MAC Act leaves questions of permanent impairment and causation for medical assessors' exclusive and conclusive determination: [141] - [158]. Spratt v Perilya Broken Hill Ltd; Spratt v Rowe (2016) 77 MVR 206; [2016] NSWCA 192 applied. Motor Accidents Authority of NSW v Mills (2010) 78 NSWLR 125; [2010] NSWCA 82; Pham v Shui (2006) 47 MVR 231; [2006] NSWCA 373; Ackling v QBE Insurance (Australia) Limited and Anor (2009) 75 NSWLR 482; [2009] NSWSC 881; Rodger v De Gelder (2015) 71 MVR 514; [2015] NSWCA 211 considered.

JUDGMENT

1. McCOLL JA: The applicant, AAI Limited trading as AAMI (AAMI), seeks leave to appeal and to appeal from a decision of Button J dismissing its summons seeking judicial review of a determination made by the second respondent, the Proper Officer of the first respondent, the State Insurance Regulatory Authority of New South Wales (Authority). [1]
2. The third respondent, Ms Vanessa Sproule, lodged an insurance claim with AAMI seeking to recover damages in respect of injuries she said she suffered during a motor vehicle accident on 5 July 2009 involving the driving of a vehicle by her ex-partner, Mr Judd Ball. AAMI was Mr Ball's motor vehicle insurer. A dispute arose as to the extent to which Ms Sproule's permanent impairment was caused by the incident.
3. A medical assessor appointed by the Authority determined that Ms Sproule had a whole person impairment of 14%. AAMI sought a review of this assessment pursuant to s 63 of the Motor Accidents Compensation Act 1999 (NSW) (MAC Act). The review application was rejected by the Proper Officer of the Authority's Medical Assessment Service. On AAMI's subsequent application for judicial review of the Proper Officer's decision, the primary judge found that the Proper Officer's determination did not demonstrate jurisdictional or non-jurisdictional error and dismissed the application. [2]
4. The critical issue which arises for determination is whether a medical assessor conducing an assessment of the degree of a claimant's permanent impairment pursuant to Part 3.4 of the MAC Act is required to determine the legal issue whether the injuries the claimant suffered were caused by a "motor accident" within the meaning of the latter expression in s 3 of the MAC Act.
5. AAMI contended that leave to appeal is required on the basis that the judgment did not involve a matter in issue to, or of the value of, $100,000 or more. [3] Ms Sproule did not concede the amount in issue was less than $100,000, but nevertheless opposed a grant of leave to appeal. There being no evidence to establish leave is not required, [4] the Court should proceed on the basis AAMI propounds.
6. Accordingly, this is the concurrent hearing of AAMI's application for leave to appeal and, if leave be granted, the hearing of the appeal. Leave to appeal should be granted as the case raises important questions of law concerning the proper construction of the MAC Act.
7. However, for the reasons that follow, I am of the view that the appeal should be dismissed. I would reject AAMI's submission that the MAC Act required a medical assessor to make a determination as to, or characterise, what elements of an incident involving a motor vehicle during which a person was injured constituted a "motor accident" within the meaning of s 3 of the MAC Act.

Legislative framework

1. At the time of Ms Sproule's alleged motor vehicle accident, the MAC Act relevantly provided as set out below. For convenience, I refer to the relevant provisions in present tense.
2. Chapter 1 deals with preliminary matters. Section 3 contains the following definitions: "claim means a claim for damages in respect of the death of or injury to a person caused by the fault of the owner or driver of a motor vehicle in the use or operation of the vehicle. … fault means negligence or any other tort. … injury means personal or bodily injury and includes… … MAA Claims Assessment Guidelines means guidelines issued by the Authority under Part 4.1 and in force. MAA Medical Guidelines means guidelines issued by the Authority under Part 3.1 and in force. … motor accident means an incident or accident involving the use or operation of a motor vehicle that causes the death of or injury to a person where the death or injury is a result of and is caused (whether or not as a result of a defect in the vehicle) during: (a) the driving of the vehicle, or (b) a collision, or action taken to avoid a collision, with the vehicle, or (c) the vehicle's running out of control." [5]
3. Section 3A(1) provides: "3A General restrictions on application of Act (1) This Act (including any third-party policy under this Act) applies only in respect of the death of or injury to a person that is caused by the fault of the owner or driver of a motor vehicle in the use or operation of the vehicle and only if the death or injury is a result of and is caused (whether or not as a result of a defect in the vehicle) during: (a) the driving of the vehicle, or (b) a collision, or action taken to avoid a collision, with the vehicle, or (c) the vehicle's running out of control. … (2) This Act (including any third-party policy under this Act) does not apply in respect of an injury that arises gradually from a series of incidents." [6]
4. The application of Chapters 3 - 6 in respect of death or injury that results from the use or operation of a motor vehicle is relevantly limited to death or injury that is caused by a motor accident for which the vehicle has motor accident insurance cover. [7]
5. The objects of the MAC Act include providing "compensation for compensable injuries sustained in motor accidents, and to encourage the early resolution of compensation claims". [8] Section 5(2) relevantly provides: "(2) It must be acknowledged in the application and administration of this Act: … (b) that the law (both the enacted law and the common law) relating to the assessment of damages in claims made under this Act should be interpreted and applied in a way that acknowledges the clear legislative intention to restrict the level of non-economic loss compensation in cases of minor injuries…"
6. Chapter 3 of the MAC Act deals with "Motor accident injuries". It applies "to and in respect of an injury caused by a motor accident occurring after the commencement of this Act" and "whether or not there is a third-party policy in respect of liability for the injury." [9]
7. Part 3.1 deals with preliminary matters. The Authority may issue MAA Medical Guidelines (Medical Guidelines) with respect to, among other matters, the assessment of the degree of permanent impairment of an injured person as a result of an injury caused by a motor accident. [10] The Medical Guidelines must be developed in consultation with relevant medical colleges, including the Royal Australasian College of Physicians, the Royal Australasian College of Surgeons, the Royal Australian College of General Practitioners, the Australian Orthopaedic Association, the para-medical professional associations and other relevant colleges and associations. [11]
8. The Authority has issued the following Medical Guidelines pursuant to s 44: 1. the Permanent Impairment Guidelines, issued with respect to the assessment of the degree of permanent impairment of an injured person as a result of an injury caused by a motor accident; [12] and 2. the Medical Assessment Guidelines, issued with respect to the procedures for the referral of disputes for assessment or review of assessments, and the procedure for assessment and review of assessments, under Part 3.4 of the MAC Act. [13]
9. Part 3.4 deals with "Medical assessment" and relevantly provides: "57 Definitions In this Part: medical assessment matters means any of the matters referred to in section 58. medical assessor means a person appointed under this Part to make an assessment under this Part. medical assessors review panel means a panel of medical assessors convened under this Part to review an assessment under this Part. medical dispute means a disagreement or issue to which this Part applies." (Emphasis in original)
10. The Authority is required to establish a unit known as the Motor Accidents Medical Assessment Service, to consist of medical assessors and such officers of the Authority as the Authority determines. [14] The Authority is required to appoint medical practitioners and other suitably qualified persons as medical assessors for the purposes of Pt 3.4. [15]
11. Section 58 provides: "58 Application (1) This Part applies to a disagreement between a claimant and an insurer about any of the following matters (referred to in this Part as medical assessment matters): (a) whether the treatment provided or to be provided to the injured person was or is reasonable and necessary in the circumstances, (b) whether any such treatment relates to the injury caused by the motor accident, … (d) whether the degree of permanent impairment of the injured person as a result of the injury caused by the motor accident is greater than 10%. … (2) This Part also applies to any issue arising about such a matter in proceedings before a court or in connection with the assessment of a claim by a claims assessor." (bold in original, italics added)
12. A medical dispute can be referred to the Authority for assessment under Pt 3.4 by either party to the dispute or by a court or claims assessor. The Authority is to arrange for the dispute to be referred to one or more medical assessors. [16]
13. Section 61 deals with the status of medical assessments as follows: "61 Status of medical assessments (1) The medical assessor or assessors to whom a medical dispute is referred is or are to give a certificate as to the matters referred for assessment. (2) Any such certificate as to a medical assessment matter is conclusive evidence as to the matters certified in any court proceedings or in any assessment by a claims assessor in respect of the claim concerned. … (4) In any court proceedings, the court may (despite anything to the contrary in this section) reject a certificate as to all or any of the matters certified in it, on the grounds of denial of procedural fairness to a party to the proceedings in connection with the issue of the certificate, but only if the court is satisfied that admission of the certificate as to the matter or matters concerned would cause substantial injustice to that party. (5) If a certificate as to any matter is rejected under subsection (4), the court is to refer that matter again for assessment under this Part and adjourn the proceedings until a further certificate is given and admitted in evidence in the proceedings. (6) However, if a certificate as to whether or not the degree of permanent impairment of the injured person is greater than 10% is rejected under subsection (4), the court may, if it considers it appropriate, substitute a determination of the court as to the degree of permanent impairment of the injured person (assessed by the court in accordance with section 133) instead of referring that matter again for assessment under this Part. (7) Except as provided by subsection (6), a court may not substitute its own determination as to any medical assessment matter. (8) This section: (a) does not prevent a court from referring a matter again for assessment under this Part (as provided for by section 62), and (b) does not require a court to refer a matter again for assessment under this Part if the matter is not a medical assessment matter. (9) A certificate is to set out the reasons for any finding by the medical assessor or assessors as to any matter certified in the certificate in respect of which the certificate is conclusive evidence. … (11) If a medical assessor is satisfied that a certificate under this section contains an obvious error, the medical assessor may issue a replacement certificate to correct the error." (Emphasis added)
14. Pursuant to s 62, a matter can be referred for further medical assessment in the following circumstances: "62 Referral of matter for further medical assessment (1) A matter referred for assessment under this Part may be referred again on one or more further occasions in accordance with this Part: (a) by any party to the medical dispute, but only on the grounds of the deterioration of the injury or additional relevant information about the injury, or (b) by a court or claims assessor. (1A) A matter may not be referred again for assessment by a party to the medical dispute on the grounds of deterioration of the injury or additional relevant information about the injury unless the deterioration or additional information is such as to be capable of having a material effect on the outcome of the previous assessment. (1B) Referral of a matter under this section is to be by referral to the officer of the Authority designated by the Authority for the purpose (in this Part referred to as the "proper officer of the Authority"). (2) A certificate as to a matter referred again for assessment prevails over any previous certificate as to the matter to the extent of any inconsistency."
15. Section 63 deals with the review of a medical assessment by a review panel and relevantly provides: "63 Review of medical assessment by review panel (1) A party to a medical dispute may apply to the proper officer of the Authority to refer a medical assessment under this Part by a single medical assessor to a review panel of medical assessors for review. (2) An application for the referral of a medical assessment to a review panel may only be made on the grounds that the assessment was incorrect in a material respect. … (3) The proper officer of the Authority is to arrange for any such application to be referred to a panel of at least 3 medical assessors, but only if the proper officer is satisfied that there is reasonable cause to suspect that the medical assessment was incorrect in a material respect having regard to the particulars set out in the application. (3A) The review of a medical assessment is not limited to a review only of that aspect of the assessment that is alleged to be incorrect and is to be by way of a new assessment of all the matters with which the medical assessment is concerned. (4) The review panel may confirm the certificate of assessment of the single medical assessor, or revoke that certificate and issue a new certificate as to the matters concerned. (5) If on the review of a medical assessment of a single medical assessor on which a combined certificate assessment is based a new certificate is issued by the review panel, the review panel is also to issue a new combined certificate to take account of the results of the review. (6) Section 61 applies to any new certificate or new combined certificate issued under this section. (7) The MAA Medical Guidelines may limit the time within which an application under this section may be made."
16. Medical assessments under Pt 3.4 of the MAC Act are subject to relevant provisions of the Medical Guidelines relating to the procedures for the referral of disputes for assessment or review of assessments and the procedure for assessment. [17]
17. Chapter 4 of the MAC Act deals with "Motor accident claims". It applies to and in respect of a "claim relating to a motor accident" which occurred after the MAC Act commenced. [18]
18. Part 4.2 deals with "Claims and other preliminary matters."
19. Pursuant to s 70(1), "[u]nless a police officer attended the motor accident, a motor accident that gives rise to a claim must be reported to a police officer by or on behalf of the claimant within 28 days after the motor accident". A claim must be made within 6 months after the relevant date for the claim. [19]
20. Part 4.3 deals with duties with respect to claims. It is the duty of an insurer to endeavour to resolve a claim, by settlement or otherwise, as justly and expeditiously as possible. [20] In particular, it is the duty of an insurer to give written notice to the claimant as expeditiously as possible whether the insurer admits or denies liability for the claim, but in any event within 3 months after the claimant gave notice of the claim under s 72. [21]
21. If the insurer admits liability, it is obliged to make a reasonable offer of settlement to the claimant within the time limits set out in s 82(1). Further, once liability has been admitted (wholly or in part) or determined (wholly or in part) against the person against whom the claim is made, it is the duty of an insurer to make payments to or on behalf of the claimant in respect of expenses set out in s 83(1), to the extent to which those payments are reasonable and necessary in the circumstances, and are properly verified, and relate to the injury caused by the fault of the owner or driver of the motor vehicle to which the third-party policy taken to have been issued by the insurer relates. [22]
22. Part 4.4 deals with claims assessment and resolution. It applies to any claim, whether or not the insurer admits or denies liability. [23]
23. The Authority is required to establish the Motor Accidents Claims Assessment and Resolution Service (Service), to consist of claims assessors and such other officers of the Authority as the Authority determines. [24] For the purposes of Pt 4.4, claims assessors are persons designated as such by the Authority, who, in its opinion, are suitably qualified to be claims assessors under Pt 4.4. [25] The Minister is to appoint an Australian lawyer as Principal Claims Assessor. [26]
24. Division 1A deals with "Document exchange and settlement conference before claims assessment". It does not, however apply where, relevantly, the claim is exempt from assessment under Pt 4.4 pursuant to s 92(1)(a), or the insurer wholly denies liability in respect of the claim. [27]
25. Division 2 deals with the assessment of claims. A claim can be referred to the Authority by the claimant or the insurer, or both, for assessment under Pt 4.4. [28]
26. A claimant is not entitled to commence court proceedings against another person in respect of a claim unless the Principal Claims Assessor has issued a certificate in respect of the claim under s 92 (Claims exempt from assessment). [29] A claim is exempt from assessment under Pt 4.4 if it is of a "kind that is exempt under MAA Claims Assessment Guidelines" [30] (Claims Assessment Guidelines) or if a claims assessor has made a preliminary assessment of the claim and has determined (with the approval of the Principal Claims Assessor) that it is not suitable for assessment under Pt 4.4. [31]
27. The Claims Assessment Guidelines are made pursuant to s 69(1) which appears in Pt 4.1. Section 69(1) authorises the Authority to issue guidelines for or with respect to procedures for the assessment of claims under Pt 4.4 and associated matters. The Authority is to consult the Insurance Council of Australia Limited, the Council of the Bar Association and the Council of the Law Society about any proposed Claims Assessment Guidelines. [32]
28. Clause 8.11 of the Claims Assessment Guidelines provides: [33] "8.11 For the purpose of section 92(1)(a), the PCA shall issue a certificate of exemption when satisfied that, as at the time of the consideration of the application, the claim involves one or more of the following circumstances: 8.11.1 the fault of the owner or driver of a motor vehicle in the use or operation of the vehicle is denied by the insurer of that vehicle in its written notice issued in accordance with section 81; … 8.11.5 the insurer has declined to indemnify the owner or driver of the motor vehicle against which the claim is made under the third-party policy provided for in section 10 of the Act; … " [34]
29. Section 94 which appears in Pt 4.4, Div 2 relevantly provides "94 Assessment of claims (1) The claims assessor is, in respect of a claim referred to the assessor for assessment, to make an assessment of: (a) the issue of liability for the claim (unless the insurer has accepted liability), and (b) the amount of damages for that liability (being the amount of damages that a court would be likely to award). (2) Such an assessment is to be made having regard to such information as is conveniently available to the claims assessor, even if one or more of the parties to the assessment does not co-operate or ceases to co-operate. (3) The assessment is to specify an amount of damages. (4) The claims assessor must, as soon as practicable, after an assessment issue the insurer and claimant with a certificate as to the assessment. (5) The claims assessor is to attach a brief statement to the certificate, setting out the assessor's reasons for the assessment. (6) If the Principal Claims Assessor is satisfied that a certificate as to an assessment or a statement attached to the certificate contains an obvious error, the Principal Claims Assessor may issue, or approve of the claims assessor issuing, a replacement certificate or statement to correct the error." (Emphasis added)
30. Section 94A confers comprehensive powers in relation to costs on costs assessors. In making an assessment and specifying damages under s 94 in respect of a claim, a claims assessor may include in the assessment an assessment of the claimant's costs (including costs for legal services and fees for medico-legal services) in the matter. [35] Matters to which the claims assessor is to have regard in assessing costs include the amount of any written offer of settlement made by either party to the matter and the matters set out in s 363 of the Legal Profession Act 2004 (NSW). [36]
31. An assessment under Pt 4.4 of the issue of liability for a claim is not binding on any party to the assessment. [37] However, an assessment under Pt 4.4 of the amount of damages for liability under a claim is binding on the insurer, which is obliged to pay to the claimant the amount of damages specified in the certificate as to the assessment if the insurer accepts liability under the claim, and the claimant accepts the amount of damages in settlement of the claim within 21 days after the certificate of assessment is issued. [38]
32. Pursuant to s 96, certain disputes in connection with claims, which might broadly be described as of the nature of that which might be the subject of a separate decision pursuant to UCPR Pt 28, may be the subject of assessment. By way of illustration, such an assessment may be made of the question whether, for the purposes of s 34 (Claim against Nominal Defendant where vehicle not identified), there has been due inquiry and search to establish the identity of a motor vehicle. [39]
33. Claims assessors have power to give a direction in writing to a party to an assessment under Pt 4.4 requiring the party to produce information [40] and to provide documents and information produced or furnished by a party to an assessment to any other party to the assessment. [41] The Principal Claims Assessor may, in the circumstances referred to in s 102, issue a summons requiring the attendance of a party to an assessment at an assessment conference.
34. At the proceedings before a claims assessor (assessment conference), a party to an assessment is entitled to be represented by an Australian legal practitioner or an agent and is entitled to such representation or assistance (for example, the assistance of an interpreter) as may be necessary to enable the party to communicate adequately at the assessment conference. The claims assessor must take into account any written submission prepared by an Australian legal practitioner acting for a party to the assessment. If the claims assessor is satisfied that sufficient information has been supplied to him or her in connection with an assessment, the assessor may exercise functions under the MAC Act without holding any assessment conference or other formal hearing. [42]
35. Part 4.5 deals with "Court proceedings on claims". Proceedings in respect of a claim may be taken in any court of competent jurisdiction. [43] Pursuant to s 108, court proceedings against another person in respect of a claim may not be commenced unless either the Principal Claims Assessor has issued a certificate in respect of the claim under s 92, or a claims assessor has issued a certificate in respect of the claim under s 94. Section 109 deals with time limitations on the commencement of court proceedings and is additional to s 108. The insurer of a person against whom a claim is made may give the claimant notice requiring the claimant to commence court proceedings in respect of the claim if the claimant has been entitled to commence the proceedings for a period of at least 6 months, and at least 18 months have elapsed since the date of the motor accident to which the claim relates. [44]
36. If significant evidence is adduced in the court proceedings in respect of a claim for which a claims assessor has issued a certificate under s 94, the court is required to adjourn the proceedings until the party who has adduced the evidence has referred the matter for further assessment under Pt 4.4, and a claims assessor has issued a further certificate under s 94 in respect of the claim. [45]
37. Chapter 5 of the MAC Act deals with awards of damages. It applies "to and in respect of an award of damages which relates to the death of or injury to a person caused by the fault of the owner or driver of a motor vehicle in the use or operation of the vehicle." [46] It applies to and in respect of the assessment of damages by a claims assessor under Pt 4.4 in the same way as it applies to and in respect of an award of damages by a court. [47]
38. A court cannot award damages to a person in respect of a motor accident contrary to Chapter 5. [48]
39. Part 5.2 deals with damages for economic loss. Section 125 caps awards for past or future economic loss to the extent that the injured or deceased person's net weekly earnings would (but for the injury or death) have exceeded $2,500. [49] A court cannot make an award of damages for future economic loss unless the claimant first satisfies the court that the assumptions about future earning capacity or other events on which the award is to be based accord with the claimant's most likely future circumstances but for the injury. [50] Section 127 requires a prescribed discount rate to be used when assessing damages for future economic loss. Section 128 deals with the maximum amount for the provision of certain attendant care services. Section 129 deals with respite care.
40. Part 5.3 deals with damages for non-economic loss. No damages may be awarded for non-economic loss unless "the degree of permanent impairment of the injured person as a result of the injury caused by the motor accident is greater than 10%." [51]
41. Section 132 provides: "132 Assessment of impairment required before award of damages for non-economic loss if dispute over impairment threshold (1) If there is a dispute about whether the degree of permanent impairment of an injured person is sufficient for an award of damages for non-economic loss, the court may not award any such damages unless the degree of permanent impairment has been assessed by a medical assessor under Part 3.4 (Medical assessment). Note. The assessment of the medical assessor under Part 3.4 is conclusive in proceedings before the court - see section 61. (2) The court may, at any stage in proceedings for an award of damages for non-economic loss, refer the matter for assessment of the degree of permanent impairment under Part 3.4. (3) A medical assessor may decline to make an assessment under Part 3.4 of the degree of permanent impairment of an injured person until the assessor is satisfied that the impairment caused by the injury has become permanent. Court proceedings with respect to any such matter may be adjourned until the assessment is made. (4) Nothing in this section prevents: (a) the degree of impairment being re-assessed under Part 3.4, or (b) a claim from being settled at any time." (Emphasis added)
42. Section 133 deals with how the degree of permanent impairment is assessed and provides: "133 Method of assessing degree of impairment (1) The assessment of the degree of permanent impairment of an injured person as a result of the injury caused by a motor accident is to be expressed as a percentage in accordance with this Part. (2) The assessment of the degree of permanent impairment is to be made in accordance with: (a) MAA Medical Guidelines issued for that purpose, or (b) if there are no such guidelines in force - the American Medical Association's Guides to the Evaluation of Permanent Impairment, Fourth Edition. (3) In assessing the degree of permanent impairment under subsection (2)(b), regard must not be had to any psychiatric or psychological injury, impairment or symptoms, unless the assessment of the degree of permanent impairment is made solely with respect to the result of a psychiatric or psychological injury." (Emphasis added)
43. The MAC Act was intended to provide a new scheme of compulsory third-party insurance and payment of compensation relating to the death of or injury to persons as a consequence of motor accidents. [52]
44. The Explanatory Memorandum referred to the principal changes effected by the MAC Act which included: "(d) The establishment of a system of independent medical assessment to resolve disputes about treatment, rehabilitation and other related medical matters. … (f) The establishment of a Motor Accidents Claims and Resolution Service within the Authority to assess disputed claims before court proceedings can be commenced to assist in the resolution of disputes about claims. … (h) The modification of the principles applicable to the award of damages, in particular: (i) changing the current threshold tests that apply before a person is entitled to damages for non-economic loss (e.g. pain and suffering) to at least 10% permanent impairment on a 'whole of person' medical assessment, and (ii) excluding compensation for economic loss for the first 5 days of loss of earnings and providing a cap on the weekly amount of loss of earnings similar to that applying to damages for work-related injuries. … Part 3.1 Preliminary This Part deals with certain preliminary matters for the operation of Chapter 3. These matters include the definitions of certain words for the purposes of that Chapter, the injuries to which the Chapter applies and the issuing of Medical Guidelines by the Motor Accidents Council as part of the Council's oversight of medical assessment. The Medical Guidelines may approve appropriate treatment for injuries, appropriate rehabilitation procedures and set out procedures for the assessment of permanent impairment and the assessment of medical and related disputes. … Part 3.4 Medical assessment This Part provides for the new arrangements outlined above for independent medical assessment in the case of disputes between a claimant and an insurer about certain matters related to medical or related treatment for a motor accident injury and the degree of permanent impairment a person has suffered from such an injury. The Part provides for the appointment of medical assessors, assessment procedures, costs of assessments and the review of such assessments by a review panel."
45. In the Second Reading Speech to the Bill which became the MAC Act, [53] the Special Minister of State, the Hon John Della Bosca, said: "Part 3.4 provides an accessible means of getting early, quick and independent decisions on treatment, rehabilitation and care outside of the court system. All disputes over the treatment, rehabilitation and care an injured person requires, the degree of permanent impairment an injured person has or whether an injury has stabilised will be referred to the MAA, which will refer the disputes to a relevant medical expert from a list maintained by the MAA. Further medical assessments will be allowed if a person's condition deteriorates, and there is provision for review of an assessment by three medical experts. Medical assessment decisions on the treatment, rehabilitation and care of injured persons pending the finalisation of their claim, and decisions on degree of permanent impairment and whether an injury has stabilised, are binding. These reforms permit early, quick, objective decisions on medical issues to be made outside of the court system. The majority of motor accident matters do not involve difficult legal issues and are essentially a determination of an amount of compensation. While very few matters end up being decided in a court, over half of all motor accident claims involve claimants commencing court proceedings. Claims are prepared on an adversarial basis with attendant high level of legal costs. …. The main change to damages is to introduce an objective assessment of impairment as a gateway for non-economic loss. … Under the provisions of the bill no damages will be paid for non-economic loss unless the person is assessed as having more than 10 per cent permanent impairment. An objective method for determining the degree of permanent impairment will be used, such as the American Medical Association's Guides to Permanent Impairment. … Disputes over whether the 10 per cent permanent impairment gateway is reached will be resolved using the medical assessment process outlined in Part 3.4." (Emphasis added) [54]

Permanent Impairment Guidelines

1. The Permanent Impairment Guidelines were published on 1 October 2007.
2. Clauses 1.7 - 1.9 of the Permanent Impairment Guidelines deal with the causation of injury as follows: "Causation of injury 1.7 An assessment of permanent impairment is as prescribed under section 58(1)(d) of the Motor Accidents Compensation Act 1999. The assessment should determine the degree of permanent impairment of the injured person as a result of the injury caused by the motor accident. A determination as to whether the claimant's symptoms and impairment are related to the accident in question is therefore implied in all such assessments. Assessors should be aware of the relevant provisions of the AMA 4 Guides, as well as the common law principles that would be applied by a court (or claims assessor) in considering such issues. [55] 1.8 Causation is defined in the Glossary at page 316 of the AMA 4 Guides as follows: 'Causation means that a physical, chemical, or biologic factor contributed to the occurrence of a medical condition. To decide that a factor alleged to have caused or contributed to the occurrence or worsening of a medical condition has, in fact, done so, it is necessary to verify both of the following. (a) The alleged factor could have caused or contributed to worsening of the impairment, which is a medical determination. (b) The alleged factor did cause or contribute to worsening of the impairment, which is a non-medical determination'. This therefore involves a medical decision and a non-medical informed judgement. 1.9 There is no simple common test of causation that is applicable to all cases, but the accepted approach involves determining whether the injury (and the associated impairment) was caused or materially contributed to by the motor accident. The motor accident does not have to be a sole cause as long as it is a contributing cause, which is more than negligible. Considering the question 'Would this injury (or impairment) have occurred if not for the accident?' may be useful in some cases, although this is not a definitive test and may be inapplicable in circumstances where there are multiple contributing causes." [56] (Emphasis in original).
3. Clauses 1.33 - 1.35 deal with "Pre-existing impairment" as follows: "Pre-existing impairment 1.33 The evaluation of the permanent impairment may be complicated by the presence of an impairment in the same region that existed prior to the relevant motor accident. If there is objective evidence of a pre-existing symptomatic permanent impairment in the same region at the time of the accident, then its value should be calculated and subtracted from the current whole person impairment value. If there is no objective evidence of pre-existing symptomatic permanent impairment, then its possible presence should be ignored. 1.34 The capacity of an assessor to determine a change in physical impairment will depend upon the reliability of clinical information on the pre-existing condition. To quote the AMA 4 Guides page 10, 'For example, in apportioning a spine impairment, first the current spine impairment would be estimated, and then impairment from any pre-existing spine problem would be estimated. The estimate for the pre-existing impairment would be subtracted from that for the present impairment to account for the effects of the former. Using this approach to apportionment would require accurate information and data on both impairments'. Refer to 7.18 for the approach to a pre-existing psychiatric impairment. 1.35 Pre-existing impairments should not be assessed if they are unrelated or not relevant to the impairment arising from the motor vehicle accident."
4. Clause 1.36 provides: "Subsequent injuries 1.36 The evaluation of permanent impairment may be complicated by the presence of an impairment in the same region that has occurred subsequent to the relevant motor accident. If there is objective evidence of a subsequent and unrelated injury or condition resulting in permanent impairment in the same region its value should be calculated. The permanent impairment resulting from the relevant motor accident should also be calculated. If there is no objective evidence of the subsequent impairment its possible presence should be ignored."

Medical Assessment Guidelines

1. Chapter 11 of the Medical Assessment Guidelines deals with assessment procedure. In conducting an assessment a medical assessor, including a member of any review panel, may determine the assessor's own procedure and is not bound by the rules of evidence and may inquire into any issue in such manner as they think fit. [57]
2. The effect of cl 11.1 is that in the event a court referred a matter for further medical assessment pursuant to s 62(1), a medical assessor in inquiring into any issue "in such manner as they think fit", "could and would take note of the court's reasons". [58]

Factual background

1. On 7 May 2006 Ms Sproule was involved in a motor vehicle accident. Her insurance claim in respect of that accident was settled on 17 September 2009.
2. On 5 July 2009 Ms Sproule sustained injuries in an altercation with her ex-boyfriend, Mr Judd Ball, in an incident which AAMI contends comprised five phases, only some of which involved a motor vehicle. The primary judgment usefully set out a brief summary of the incident which I have annotated to identify four of AAMI's phases: "[7] Although there is a lack of clarity about precisely what occurred, [Ms Sproule] asserts [phase 1] that Mr Ball became violent and physically assaulted her whilst he was a passenger in her vehicle. She claims that he repeatedly punched her face and head, before pushing her out of the vehicle into oncoming traffic. [8] [phase 2] After taking control of the vehicle and driving a short distance, Mr Ball reversed the vehicle towards [Ms Sproule], causing her to jump over a small brick fence. [phase 3] Mr Ball then exited the vehicle and began to assault [Ms Sproule], before [phase 4] forcing her back into the vehicle [phase 4] and driving off at high speed. Fearing for her life, she claims that she jumped out of the moving vehicle and hid from Mr Ball until emergency services arrived."
3. The fifth phase, according to AAMI, occurred entirely outside the vehicle, which was stationary. It involved Mr Ball screaming at Ms Sproule outside a block of units, smashing her mobile phone, grabbing her and attempting to take her into the block of units.
4. Ms Sproule lodged a claim in respect of the incident on 1 July 2011.
5. On 5 April 2012 Ms Sproule lodged an application for assessment of a permanent impairment dispute by the Authority's Medical Assessment Service (MAS). She used a form approved by the Authority for use if "[t]here is a dispute between the claimant and the insurer about whether the degree of permanent impairment of the injured person as a result of the injury caused by the motor accident is greater than 10%".
6. In response to section 6, asking the claimant to list the injuries caused by the accident which were considered to give rise to "an assessable degree of permanent impairment in accordance with the MAA's Permanent Impairment Guidelines and the American Medical Association's Guides to the Evaluation of Permanent Impairment Fourth Edition", Ms Sproule inserted under the headings "Bodily location of injury", "Injury type" and "What aspects of this injury are in dispute?", "Head", "PTSD" and "Degree of impairment" respectively.
7. Ms Sproule attached a number of documents to her application. One required "Personal details". In response to a question asking whether police action was going to be taken, Ms Sproule inserted "yes", adding: "Assault occasioning actual bodily harm - drive recklessly or speed dangerously - take and drive conveyance without consent of owner."
8. Under the heading "Description of the accident", Ms Sproule wrote: "The vehicle mounted the footpath and collided with me, then driver forced into vehicle then drove vehicle in a reckless and furious manner at excessive speed." [sic, as in original]
9. A psychiatrist's report from a Dr Clark attached to the application described the incident in dramatic terms as involving Ms Sproule as having been "captive" in the car driven by "an aggressive stalker, who had harassed her in the past, and she had an AVO on him." It diagnosed her as suffering from "Post-traumatic Stress Disorder with ensuing Severe or Major Depression" and assessed her whole person impairment at 24%.
10. In a medical certificate attached to Ms Sproule's Personal Injury Claim Form, completed by a Dr Boddy, who appears to have been in the Emergency Department of Westmead Hospital on the night of the incident, in response to the question "Are the injuries or conditions consistent with the circumstances of the motor accident described to you?" the doctor marked "No" and wrote in brackets "Assault". The doctor diagnosed and described Ms Sproule's injury as "Blunt trauma [secondary] to alleged assault".
11. In its reply, AAMI disputed the information Ms Sproule had given in response to section 6 of her application for assessment of a permanent impairment dispute. It identified, relevantly, a dispute relating to the degree of impairment in respect of Ms Sproule's assertion she suffered PTSD. In addition in the column asking what aspects of the injury were in dispute, AAMI inserted the word "causation". Finally, AAMI inserted an entry across three columns of what appeared to be a pro forma document stating: "The Insurer does not concede that the injuries alleged by the claimant were sustained in a 'motor accident' nor that any alleged injuries result in permanent impairment exceeding 10%."
12. AAMI attached submissions to its reply which noted Ms Sproule only sought to have her "psychological injuries assessed" and sought also to have her "alleged physical injuries" assessed. The submissions set out included the following: "3. The assessment of permanent impairment is complicated due to two primary factors. Firstly, AAMI notes that the claimant was involved in a prior motor vehicle accident on 7 May 2006 in which she sustained similar injuries to those now complained of (R3). Secondly, AAMI submits that there are serious questions as to whether the claimant was injured as a result of a motor accident or as a result of the assaults perpetrated by Judd Ball."
13. In paragraphs 5 - 7, the submissions described various parts of the 5 July incident, including Mr Ball pushing Ms Sproule out of the car, hitting her on her head and reversing the vehicle towards her. The gravamen of its submission that there had not been a "motor accident" appeared to be because there were no contemporaneous reports that she had been "hit by a motor vehicle" or "involved in an accident".
14. AAMI's submissions then referred to a number of different accounts it asserted Ms Sproule had given in relation to the events of 5 July 2009. At the conclusion of that recitation, it stated: "13. When the various versions are considered together it is evident that the claimant was not in fact injured as a result of a motor accident. One cannot be confident that, absent independent corroboration, what the claimant says at a given time about past events is what actually happened. Clearly, it is doubtful that the claimant was in fact hit by the vehicle on the night of the assault or that it [sic, the vehicle] was in fact involved in an accident."
15. AAMI attached to its reply two statements Ms Sproule made to the police concerning the incident and the Police Report about it.

Medical assessment certificate

1. On 15 August 2012 a medical assessor, Dr Sharon Reutens, issued a certificate under Part 3.4 of the MAC Act, which stated: "The following injuries caused by the motor accident give rise to a permanent impairment which IS GREATER THAN 10%: ● Post Traumatic Stress Disorder (PTSD) ● Major Depression ● Panic Attacks Details of the assessment are set out in the reasons below, which form part of this certificate." (Emphasis in original)
2. It is apparent from Dr Reutens' reasons that she had been provided with Ms Sproule's claim and supporting documents and AAMI's reply and supporting documents. Dr Reutens also recorded that Ms Sproule attended her for the purposes of the assessment and resolution of the following "medical disputes in accordance with Part 3.4" of the MAC Act: "[W]hether the degree of permanent impairment of the injured person as a result of injury caused by the motor accident is greater than 10%." (Emphasis in original)
3. Dr Reutens' reasons set out Ms Sproule's pre-accident medical history, pre-accident psychiatric history (referring in this respect to the 2006 motor vehicle accident), Ms Sproule's psychosocial history, her personal history and pre-accident functioning. They then addressed the "history of the motor accident" and recounted Ms Sproule's version of the circumstances in which she was injured. This version included the five phases AAMI identifies, albeit that Dr Reutens did not so describe them. The reasons also set out the history of Ms Sproule's symptoms and treatment following the incident, and the details of injuries or conditions sustained after the "motor accident".
4. Under the heading "Review of Documentation", Dr Reutens noted AAMI's submissions concerning the various documents which made "no mention of [Ms Sproule] being hit by a motor vehicle or being involved in an accident" and, too, a police report dated 5 July 2009 which "noted that a witness heard the claimant screaming 'help me' and observed a grey sports utility vehicle reverse towards the female, mount the [kerb] and continue to reverse towards [Ms Sproule, who] jumped over the witness' fence to avoid being hit by the reversing vehicle."
5. Under the heading "Conclusions" and the sub-heading "Diagnosis and Causation", Dr Reutens summarised the matters to which she had referred earlier in her reasons, including Ms Sproule's history and stated: "Ms Sproule is a twenty-eight year old woman who was involved in a motor vehicle accident in 2009 in the context of what was described as repeated assaults and kidnapping by a former boyfriend. During the course of these events she believed several times that she was going to die. She was thrown onto the road and her car was reversed in what she believed was an attempt to kill her. … The history is consistent with a worsening of Ms Sproule's mental state following the 2009 motor vehicle accident. The assaults by Mr Ball and the ongoing fear that he will continue to stalk her or assault her in the future have contributed to her current mental state. The motor vehicle accident (the car reversing into her) is, in my opinion, another substantial cause of her current mental state. Summary of Injuries Listed by the Parties and Caused by the Accident The following injuries WERE caused by the motor accident: ● Chronic post-traumatic stress disorder. ● Chronic major depressive disorder. ● Panic attacks. These conditions are all interrelated and are best described as reformulation of the listed PTSD." [59] (emphasis in italics added)
6. Under that part of section 7 of her reasons headed "Determinations", and that part dealing with "Apportionment", Dr Reutens noted that "[t]here was a pre-existing impairment in the form of a major depressive episode." It was common ground that that was related to the 2006 motor vehicle accident. Dr Reutens noted that treatment had made "a moderate difference to [Ms Sproule's] impairment", a conclusion which required an upward adjustment to allow for the percentage improvement in order to assess Ms Sproule's permanent impairment relative to the position she would have been in if the tort had not been committed. [60]
7. Dr Reutens set out the following in a table at the conclusion of her reasons: "A Current % permanent impairment 17% B Pre-existing/subsequent % permanent impairment 5% C Adjustments % for effects of treatment 2% Final % permanent impairment 14%" [61] (Emphasis in original)
8. As the primary judge observed: [62] "[T]he certificate made no effort to differentiate between those injuries that may have arisen because of a motor accident or motor accidents that occurred on 5 July 2009, and those injuries that may have arisen because of other acts of Mr Ball on that occasion that were not motor accidents".

Review application

1. On 18 September 2012 AAMI sought a review of Dr Reutens' assessment pursuant to the MAC Act, s 63. It identified the relevant error in her certificate as being found in "Paragraph 4, page 17". AAMI contended, and Ms Sproule did not dispute, that that was an incorrect reference to the paragraph of the medical assessor's reasons set out above. [63]
2. AAMI identified Dr Reutens' error as her failure "to distinguish and apportion between the various assaults alleged by the claimant against Mr Ball and the effect of what she describes as 'The motor vehicle accident (the car reversing into her) …'".
3. In the section of the application requiring identification of how the error was "material to the outcome of the assessment", the application contended that Dr Reutens: "failed to make any or any proper attempt to disentangle the consequences of the non-motor accident assaults described in her report and their consequences which she has, in effect, inappropriately lumped together as the 2009 motor accident."
4. The application then detailed various matters set out in Dr Reutens' reasons in which Ms Sproule described the incident in which she was injured, including those involving Mr Ball assaulting her, and continued: "Having identified more than one cause for the claimant's current problems, some arguably motor accidents but many clearly not, AAMI contends that Assessor Reutens has failed to apportion her permanent impairment assessment between what is compensable under the Act and what is not. That failure is a material error …".
5. On 22 November 2012 the Proper Officer dismissed AAMI's application for review of the medical assessment. He referred (at [4]) to s 63 of the MAC Act as requiring the review application to be accepted if he was satisfied "there is reasonable cause to suspect that the medical assessment is incorrect in a material respect". He identified one of the matters of which AAMI complained as being Dr Reutens' failure to disentangle the consequences of the non-motor accident assaults and wrote: "[8] Whether or not the alleged 'incidents' which took place in July 2009 constitute a 'motor accident' is not, in my view, a matter for the MAS Assessor to determine. It is a matter that the CARS Assessor or a Court will determine in due course as indicated in the CARS Preliminary Conference report of CARS Assessor Harvey dated 10 October 2012. [9] Even if I am wrong here, there is no suggestion in the applicant's submissions on how the Assessor could have apportioned the alleged incidents which all occurred on the same day within minutes of each other. The apportionment provisions in the MAA Guidelines (clause 1.33-1.35 and 7.18) are clear. They require objective evidence of a pre-existing symptomatic permanent impairment or a pre-existing psychiatric diagnosis or condition. As indicated by the Assessor, she was able to apportion between the 2006 accident and the 2009 accident but there is nothing to suggest the psychiatric impairment within the 2009 accident/incidents could be apportioned."
6. Accordingly, the Proper Officer concluded he was not satisfied that there was "reasonable cause to suspect that the medical assessment [was] incorrect in a material respect." He dismissed the review application.
7. In December 2012, AAMI's legal representatives applied pursuant to the MAC Act, s 92 to have Ms Sproule's claim exempted from the claims assessment process on two grounds. First, that "[t]he fault of the owner or driver of a motor vehicle in the use or operation of the vehicle is denied by the insurer in its written notice issued in accordance with section 81" and, secondly, that "[t]he insurer has declined to indemnify the owner or driver of the motor vehicle against which the claim is made under the third-party policy provided for in section 10 of the Act." Each of those bases for the exemption application reflected respectively clause 8.11.1 and clause 8.11.5 of the Claims Assessment Guidelines set out earlier in these reasons. [64] Ms Sproule accepted that the claim should be exempt from assessment for the reasons given by AAMI. On 31 January 2013 the Authority issued a certificate pursuant to s 92(1)(a) of the MAC Act exempting Ms Sproule's claim from assessment.
8. Ms Sproule filed a statement of claim seeking to recover damages in relation to the incident in the District Court of New South Wales on 2 April 2013.
9. On 13 June 2013 AAMI filed a motion in the District Court proceedings seeking to be joined as a party in order to argue that it had no obligation to indemnify the defendant and an order that the proceedings be dismissed pursuant to the MAC Act, s 73(5).
10. On 13 March 2014 AAMI filed a summons in the Supreme Court seeking an order in the nature of certiorari on the basis of jurisdictional error or error of law on the face of the record. AAMI sought to challenge the Proper Officer's refusal to refer Ms Sproule's permanent impairment assessment for review.

Primary judgment

1. The primary judge identified the fundamental question requiring determination on the judicial review application as follows: "Did the proper officer commit an error of law in refusing to order a review of a medical assessment, when that medical assessment did not attempt to 'disentangle' the degree to which the various components of an alleged single violent incident (some of which were said to be motor accidents as defined in the Act, and some of which were said not to be) caused psychiatric injury to Ms Vanessa Sproule?" [65] (emphasis in original)
2. AAMI contended that had the medical assessor undertaken her assessment properly, and excluded injuries that arose from acts that were not motor accidents, Ms Sproule's degree of permanent impairment would in all likelihood not have exceeded 10%, thereby (almost conclusively) foreclosing damages for non-economic loss, by way of the operation of the MAC Act. [66]
3. The primary judge accepted a number of matters. [67] First, that the Proper Officer played the role of gatekeeper, not ultimate decision maker, and that, in that sense, the test for review of a medical assessment should not be construed as being a strict one. Secondly, that the test for the Proper Officer was not whether he was affirmatively satisfied that the medical assessment was incorrect in a material respect, having regard to the particulars set out in AAMI's application. Rather, the question was whether the Proper Officer had reasonable cause to suspect that state of affairs. [68] Thirdly, that "the clear words of s 58(1)(d) confer upon a medical assessor an obligation to make an assessment of causation". [69]
4. However, his Honour held that the Proper Officer's determination did not demonstrate an error of law, whether jurisdictional or non-jurisdictional, for seven reasons: "[43] First, I do not accept that it is incumbent upon a medical assessor, in undertaking his or her functions pursuant to s 58(1)(d) of the Act, to attempt to engage in an intricate legal analysis of the meaning of causation. In particular, I do not consider that it was the intention of Parliament that a medically qualified assessor must refer to numerous decisions of the High Court of Australia and the New South Wales Court of Appeal about the concept of causation in order to understand his or her function when undertaking a medical assessment. … [45] Secondly, I also do not consider that it was the intention of Parliament that a medical assessor would be expected to engage in an analysis of the combined effect of ss 3 and 3A, each of which has its own complexities. To give but one example from the cases to which I was invited, it can be seen that in GSF (a decision of the High Court of Australia construing the question of causation in light of the provisions of a statutory predecessor of the Act) three judgments were delivered: that of McHugh J; that of the plurality; and that of Callinan J. I do not regard the proposition that a medical assessor is expected to read and understand such judgments, and to discern a ratio decidendi from them, as consonant with the purposes of the Act. Nor do I consider that it is consonant with the structure of the Act as a whole. [46] Such a task is the work of lawyers and judges, not medical assessors. Indeed, a five judge bench undertook that task in Zotti v Australian Associated Motor Insurers Ltd [2009] NSWCA 323 with regard to s 3 of the Act, without coming to a unanimous position. [47] Thirdly, it is to be remembered that a medical assessor is not determining the quantum of damages that will be paid to a claimant who has been the subject of a medical assessment that found that whole person impairment is greater than 10%. All that a medical assessment to that effect does is provide an essential pre-condition for compensation by way of damages for non-economic loss. The determination pursuant to s 58(1)(d) does not mean that there must inevitably be substantial damages for non-economic loss. [48] Fourthly, the decisions to which I was invited by the insurer demonstrate that the concept of causation at common law in the setting of the law of negligence can be very broadly understood as being founded upon material contribution. The certificate of the medical assessor is (almost) conclusive evidence that a motor accident or accidents materially contributed to whole person impairment greater than 10%. But to my mind that (almost) conclusive determination does not prohibit a trial judge from determining that other precipitants (such as acts that were not motor accidents causing psychiatric injury) were not only additional material contributors, but also were by far the more important material contributors. Again, the practical result could be that damages for non-economic loss could be very small, if not negligible. [49] Fifthly, the facts in Gonzalez may be readily distinguished. In that case there were two easily severable events: the motor accident and its aftermath. Here, the sub-events said to be motor accidents as defined and the sub-events said not to be motor accidents were thoroughly intertwined. I do not consider that the judgment in Gonzalez mandates the result for which the insurer contended, in light of the very different circumstances of this case. [50] Sixthly, turning to analyse the precise words used by the proper officer in the reasons given for the decision, I do not discern error in para [8]. To the contrary, I agree that it is not a matter for the medical assessor to determine whether an overarching incident, or particular sub-incidents within it, constitutes a 'motor accident' as defined in the Act. As I have said, I do not interpret the Act as imposing a complicated legal function upon a person who is qualified within an entirely different area of learning. [51] As for para [9], its first sentence is objectively correct: the submission of the insurer before the proper officer did not indicate how an internal apportionment was to be undertaken with regard to psychiatric injuries said to have arisen from the trauma of one alleged overarching event that contained many sub-events. [52] I do not consider that there is error in the latter section of para [9]. As for the reference to the guidelines at [9], the statement of the proper officer is objectively true: the guidelines speak explicitly of what I have called external apportionment, but say nothing of internal apportionment. To my mind, whilst not determinative of the application for review, that was not an irrelevant factor for the proper officer to take into account in determining, pursuant to s 63(2) of the Act, whether there was reasonable cause to suspect that the medical assessment provided by the assessor was incorrect in a material respect, having regard to the particulars set out in the application. [53] The proper officer concluded by asserting that there was nothing to suggest how one could divide up the aetiology of a psychiatric injury that arises from one incident that contains many sub-events very closely connected in time, space, and by way of alleged wrongdoer. That statement is not erroneous: there was indeed no material to suggest how a medical assessor could undertake that function. [54] Seventhly and finally, I do not consider that the determination of the proper officer demonstrates that he took into account any irrelevant consideration in the way that term is understood in administrative law. Nor do I consider that the determination is inherently so grossly unreasonable as to be amenable to judicial review." [70] (Emphasis in original)
5. Accordingly, the primary judge concluded that neither an analysis of the MAC Act, nor a broad analysis of the decision of the Proper Officer, nor a detailed analysis of the reasons given by the Proper Officer, established an error of law. [71]
6. Alternatively, his Honour held that even if jurisdictional error or error of law on the face of the record were established, as a matter of discretion, relief would be declined because AAMI had "a far more convenient and appropriate way" of challenging Dr Reutens' assessment: AAMI could persuade a trial judge to refer the matter for further medical assessment pursuant to s 62(1)(b) of the MAC Act. [72]

Issues on appeal

1. AAMI's draft notice of appeal, omitting the lengthy particulars, submits that the primary judge erred in the following respects: 1. Failing to hold that the Proper Officer fell into jurisdictional error in determining that he was not satisfied that there was reasonable cause to suspect that Dr Reutens' assessment was incorrect in a material respect pursuant to s 63(3) of the MAC Act. 2. Failing to hold that the Proper Officer fell into jurisdictional error in making his decision by failing to be satisfied that there was reasonable cause to suspect that Dr Reutens' assessment was incorrect in the material respect of non-compliance with the requirement under clauses 1.7 - 1.9 and 1.33 - 1.36 of the Permanent Impairment Guidelines to determine whether Ms Sproule's injury was solely caused, or materially contributed to, by a "motor accident". 3. In the alternative, failing to hold that there was a non-jurisdictional error of law on the face of the record of the Proper Officer's decision. 4. Holding that even if jurisdictional error or error of law on the face of the record were established, the Court in its discretion declined to grant relief on account of the availability to AAMI of a more convenient and appropriate relief.

AAMI's submissions

1. AAMI's fundamental contention is that Assessor Reutens failed to exercise her function of assessing whether the degree of Ms Sproule's permanent impairment "as a result of the injury caused by the motor accident" was greater than 10% within s 58(1)(d) of the MAC Act because she failed to determine which, if any, of the five phases of the 5 July 2009 incident constituted a "motor accident" as defined in s 3 of the MAC Act.
2. AAMI submits that s 58(1)(d) raises two inquiries into causation: the medical assessor must identify the "permanent impairment" that is a result of the "injury" that is "caused by" the "motor accident". Accordingly, Assessor Reutens had to determine the question whether Ms Sproule's current psychological condition had, as its very substantial cause, the particular phases that were the motor accident, as she understood it.
3. AAMI submits that s 63(3) of the MAC Act posed a low threshold to satisfy the Proper Officer that there should be a referral to a review panel. It was sufficient that the Proper Officer "identify possible error", rather than make a substantive assessment or calculation.
4. AAMI contends the legislative intention is that review by a panel should be available where there is a possibility that a medical assessment is incorrect in a material respect. AAMI argues a proper assessment has not been made if an important fact has been ignored, or the assessment has not been properly undertaken and the statutory right of a party subverted. In such circumstances the Proper Officer should reasonably be satisfied that there is cause to suspect that the assessment is incorrect in a material respect.
5. AAMI submits, further, that the primary judge erred in not recognising the Proper Officer's error. In particular, AAMI submits that the primary judge erred in holding that, as a matter of law, a medical assessor is not required to determine whether an overarching incident (or particular sub-incidents within it) constitutes a "motor accident" as defined in s 3 of the MAC Act. AAMI submits that his Honour's conclusion was inconsistent with s 58(1)(d), which requires a medical assessor to determine causation.
6. Accordingly, AAMI submits that the primary judge erred in failing to hold that the Proper Officer "proceeded upon a legally erroneous assumption as to the functions of the assessor", thereby falling into jurisdictional error in asking himself the wrong question as to whether Dr Reutens' assessment was incorrect in a material respect. Unless the assessor identified whether there was (or what was) the "motor accident", she could not determine whether the injury was "caused by a motor accident" in accordance with s 58(1)(d). AAMI submits that exercise reposed in the medical assessor, even though determining that issue may require resolution of complex factual issues of a non-medical nature.
7. AAMI's remaining submissions in respect of Ground 1 examine closely, and seek to rebut, each of the primary judge's seven reasons for dismissing the judicial review application.
8. As to Ground 2, AAMI submits that the Proper Officer erred in not suspecting incorrectness in a material respect in Dr Reutens' assessment in circumstances where that assessment failed to apply clauses 1.7 - 1.9 of the Permanent Impairment Guidelines. AAMI argues that to the extent its complaint was about failure to apportion internally, that was a complaint about causation and, accordingly, a failure to apply clauses 1.7 - 1.9 of the Permanent Impairment Guidelines.
9. AAMI submits that if the errors of which Grounds 1 and 2 complain were not jurisdictional errors, they were legal errors that appeared on the face of the Proper Officer's reasons.
10. AAMI submits the primary judge erred in finding that referral by a court under s 62(1)(b) for further assessment was a "more convenient and satisfactory remedy" entitling the Court to decline relief as a matter of discretion. [73] It contended that this was not an avenue for review of the Proper Officer's decision. When the Proper Officer did not allow a review to proceed, the medical assessor's conclusive certificate would apply in court proceedings, "exposing the insurer to the possibility of an award of damages for non-economic loss." Referral by a court did not provide an avenue for review of the certificate's validity. Furthermore, a respondent in court proceedings has no entitlement to elect that such a referral occur, nor does s 62(1)(b) enable a party to contend that a certificate is infected with legal error. A referral by the court is entirely discretionary.
11. Under these circumstances, AAMI submits that the possibility that a referral might be made under s 62(1)(b) did not constitute an equally beneficial and convenient avenue of review. Accordingly, his Honour exercised the discretion to refuse relief erroneously in a manner which would attract appellate review.

Ms Sproule's submissions

1. Ms Sproule submitted that the Proper Officer took the view that whether or not an incident constitutes a "motor accident" is not a matter for the medical assessor.
2. Ms Sproule also contended that the Proper Officer adverted to the practical difficulty with apportioning between those elements which were a "motor accident" and those which were not arising from the prescriptive terms of the Permanent Impairment Guidelines, which required "objective evidence of a pre-existing symptomatic permanent impairment or a pre-existing psychiatric diagnosis or condition". [74] Ms Sproule argued that material meeting those descriptions did not and does not exist.
3. Accordingly, even if Dr Reutens had made a finding as to which elements of the 5 July incident constituted a "motor accident", she could not have apportioned Ms Sproule's psychiatric harm between those elements which were a "motor accident" and those which were not because she could not identify either objective evidence of a pre-existing symptomatic permanent impairment, or a pre-existing psychiatric diagnosis or condition.
4. Ms Sproule submits that cll 1.7 - 1.9 of the Permanent Impairment Guidelines relate to what has been caused by "the motor accident". She argues that use of the definite article precludes conferral by the Guidelines of a wide ranging jurisdiction to inquire into the circumstances of injury so as to identify "a motor accident". Rather, it is the medical assessor's role to determine the degree of permanent impairment arising from an event which the scheme presumes constituted the motor accident.
5. Secondly, Ms Sproule submits that a dispute between an insurer and a claimant as to whether a series of elements of a single violent incident were or were not a "motor accident" is not a "medical dispute" within the terms of s 58, MAC Act.
6. Ms Sproule contends that the matters enumerated in s 58(1)(a), (b) and (d) do not include disputes as to whether an incident is a motor accident, let alone a dispute as to whether some elements within an incident are, or are not, motor accidents. She contends this is hardly surprising since neither would be a "medical assessment" in the ordinary sense of those words. Accordingly, she argues the question AAMI would have had Dr Reutens answer, and the review panel review, did not fall within matters which may be referred for medical assessment.
7. In this context, Ms Sproule submits that when s 58(1)(d) speaks of the motor accident it is not doing so in such a way as to admit of controversy as to what constitutes the motor accident. Rather, the section proceeds on the basis that the motor accident has been identified and the disagreement giving rise to a "medical assessment matter" is, relevantly, as to what, if any, degree of permanent impairment arises from that motor accident.
8. Thirdly, Ms Sproule submitted that, as a matter of fact, the referral for assessment contained in the "Dispute Details" in Dr Reutens' reasons did not raise any issue as to what constituted the relevant "motor accident". Rather, they merely identified the medical dispute as "whether the degree of permanent impairment of the injured person as a result of injury caused by the motor accident is greater than 10%". It was not suggested there was any error in framing the "Dispute Details".
9. Fourthly, Ms Sproule submits that it would be unusual if a medical assessor's role was to answer questions of law including whether a set of facts meets the statutory test for a "motor accident" within the MAC Act and, more particularly, to analyse the legal significance of the elements of a single violent incident so as to determine which, if any, of those elements met the statutory definition of a "motor accident". She contends that question is one of law and involves no medical expertise at all. Even if, as AAMI contends, it would be relatively easy to discern which of the elements constitutes a motor accident, Ms Sproule submits that AAMI failed to identify the source of power of a medical assessor to undertake such an investigation.
10. Fifthly, Ms Sproule submits that it is only once a "motor accident" has been identified, that questions of causation and apportionment arise. She argues that the question whether the relevant incident (or elements of that incident) meets the statutory description of a "motor accident" is not a question of causation. Instead, it requires an inquiry as to whether certain facts meet the statutory criteria imposed by s 3 and s 3A of the MAC Act.

Consideration

1. The focus of AAMI's submissions is on the concept of a "medical assessment matter" in s 58. However that provision cannot be considered in isolation. Resolution of the question raised on appeal involves a close consideration of the text of the MAC Act, the context, including the general purpose and policy of s 58, and, in particular, the mischief it is seeking to remedy. [75]
2. The primary object of the task of statutory construction is to construe s 58(1)(d) so that it is consistent with the language and purpose of all the provisions of the statute. [76] As the plurality emphasised in Project Blue Sky "'the context, the general purpose and policy of a provision and its consistency and fairness are surer guides to its meaning than the logic with which it is constructed.' Thus, the process of construction must always begin by examining the context of the provision that is being construed." [77]
3. The next two paragraphs of the plurality's reasons in Project Blue Sky should be set out in full: "[70] A legislative instrument must be construed on the prima facie basis that its provisions are intended to give effect to harmonious goals. Where conflict appears to arise from the language of particular provisions, the conflict must be alleviated, so far as possible, by adjusting the meaning of the competing provisions to achieve that result which will best give effect to the purpose and language of those provisions while maintaining the unity of all the statutory provisions. Reconciling conflicting provisions will often require the court 'to determine which is the leading provision and which the subordinate provision, and which must give way to the other'. Only by determining the hierarchy of the provisions will it be possible in many cases to give each provision the meaning which best gives effect to its purpose and language while maintaining the unity of the statutory scheme. [71] Furthermore, a court construing a statutory provision must strive to give meaning to every word of the provision. In The Commonwealth v Baume Griffith CJ cited R v Berchet to support the proposition that it was 'a known rule in the interpretation of Statutes that such a sense is to be made upon the whole as that no clause, sentence, or word shall prove superfluous, void, or insignificant, if by any other construction they may all be made useful and pertinent'." (footnotes omitted)
4. In my view it is apparent when s 58(1)(d) is construed by applying the principles of statutory construction to which I have referred, that the MAC Act did not require a medical assessor to make a determination as to what elements of an incident involving a motor vehicle during which a person was injured was a "motor accident" within the meaning of s 3 of the MAC Act.
5. The MAC Act does not provide "a universal, comprehensive scheme to award damages to every person who sustains an injury that was in some way connected to a motor vehicle". [78] Rather, the MAC Act establishes a system whereby claims for compensation arising from motor accidents are not determined solely in the courts, and the quantum of compensation is not ascertained (whether in court or out of court) solely in accordance with common law principles. [79]
6. When the MAC Act is carefully construed it can be seen that, despite the order in which some of its provisions appear (in particular those in Pt 3.4 dealing with medical assessment), its scheme reflects largely the logic of a common law claim for damages arising from a motor accident.
7. Generally, issues of liability and damages are dealt with either by claims assessment by claims assessors pursuant to Ch 4, Pt 4.4 or by judges in court proceedings pursuant to Pt 4.5. [80]
8. Chapter 5 deals with awards of damages. It sets out provisions that alter the common law concerning damages for personal injury in various specific ways. [81] Nevertheless, awards of damages are dealt with by a court applying Ch 5. While a claims assessor exercising the Pt 4.4 functions can assess the "amount of damages that a court would be likely to award", [82] it is apparent from both the terms of s 94(1)(b) and s 95(2) that such an assessment is not an award of damages. This conclusion is reinforced by the remonstration in s 123(1) that "[a] court cannot award damages to a person in respect of a motor accident contrary to" Ch 5. No similar warning applies to a claims assessor.
9. Finally, Ch 3 of the MAC Act establishes a special regime for the medical assessment of injuries sustained in motor accidents. [83] Of the heads of damages with which Ch 5 deals, only that dealing with non-economic loss expressly comes within the purview of that regime. That is because, by reason of Pt 5.3, what might be described as a micro-regime is established dealing with that head of damages. Under that regime, even if court proceedings are being heard, any dispute about whether the degree of permanent impairment of an injured person is sufficient for an award of damages for non-economic loss must be assessed by a medical assessor under Pt 3.4. [84]
10. The governing provisions of each of Chapters 3, 4 and 5 variously express the ambit of each chapter by reference to a descriptor which encompasses the concepts of injury and a causal relationship to a motor accident. Thus, Ch 3 "applies to and in respect of an injury caused by a motor accident", Ch 4 "applies to and in respect of a claim relating to a motor accident" and Ch 5 "applies to and in respect of an award of damages which relates to the death of or injury to a person caused by the fault of the owner or driver of a motor vehicle in the use or operation of the vehicle." [85]
11. Expressions such as "in relation to" and "in respect of" are relational terms which may denote relationships which are causal or temporal or relationships of similarity or difference. They may be designed to cover a variety of subjects and a variety of relationships between those subjects. The nature and breadth of the relationships they cover will depend upon their statutory context and purpose. [86]
12. In the present context, it can hardly be gainsaid that those governing provisions are not intended to enlarge the ambit of the MAC Act beyond that for which s 3A provides. Section 3A is the "governing provision for the application of the [MAC] Act (apart from Part 1.2) to a claim for damages by a person injured in a motor accident". [87] It was inserted in the MAC Act "to clarify that the Act applies to death or injury caused in an accident occurring during the driving of the vehicle, a collision or the vehicle running out of control and not to an injury that arises gradually from a series of incidents". [88] That causation inquiry is to be determined in accordance with s 5D and s 5E of the Civil Liability Act 2002 (NSW), Pt 1A, Divs 1 - 4 and 8 of which apply to motor accidents. [89]
13. There is, of course, no liability in negligence without damage. [90] Accordingly the s 3A gateway is predicated on there being death of or injury to a person caused by the fault of the owner or driver of a motor vehicle in the use or operation of the vehicle and only if the death or injury is a result of and is caused by a motor accident. The inquiry requires consideration of the s 3 definition of "motor accident". In order to fall within s 3A, it is necessary to identify a sufficient connection between the injuries and the driving fault. Driving which is merely the occasion for the infliction of injuries will not suffice even if it is contemporaneous with the activity which inflicts the injury. [91]
14. The question whether the plaintiff was injured in a "motor accident" is a liability issue. It is a larger issue than that relating to recovery of one head of damages, namely that for non-economic loss. In the ordinary course one would expect a liability issue would be resolved before the question whether the plaintiff qualifies for any damages arises. Such resolution would either be by an insurer's admission, a claims assessment or a court determination. However, on AAMI's submission, this is the issue a medical assessor has to determine, and, presumably, include in the s 61 certificate, which is then "conclusive evidence" in either the claims assessment or the court proceedings. [92] To state that proposition is to reveal its inherent implausibility.
15. Other contextual matters indicate that it is improbable that the legislature intended medical assessors to determine the issue of what constitutes a "motor accident".
16. First, a claim is exempt from assessment under Pt 4.4 pursuant to s 92(1)(a) if it is of a kind that is exempt under the Claims Assessment Guidelines or the regulations. [93] A claim is exempt if "the fault of the owner or driver of a motor vehicle in the use or operation of the vehicle is denied by the insurer of that vehicle in its written notice issued in accordance with section 81" or if the insurer declines to indemnify the owner or driver. [94] The words in cl 8.11.1 describe the fundamental liability issue, the basis upon which a person is entitled to claim under the MAC Act. [95] The basis upon which an insurer might decline to indemnify the owner or driver pursuant to cl 8.11.5 of the Claims Assessment Guidelines was not explored. However, the application of Chapters 3 - 6 in respect of death or injury that results from the use or operation of a motor vehicle is limited to death or injury that is caused by a motor accident for which the vehicle has motor accident insurance cover. [96] Presumably an insurer will decline indemnity if it asserts that the claim relates to an incident which was not a "motor accident" and therefore not covered by motor accident insurance. Once again, that goes to a question of liability. Thus, either basis of exemption removes the issue of whether an incident in which a person was injured or killed constituted a "motor accident" from the purview of a medical assessor.
17. Secondly, medical assessors are only appointed for the purposes of Pt 3.4. Their function is to resolve the medical disputes referred to in s 58 which may be referred to them by either party to the dispute, a court or a claims assessor. [97] They do not play a role in determining issues arising under Ch 4 or Ch 5, save to the extent a certificate such an assessor issues is "conclusive evidence as to the matters certified in any court proceedings or in any assessment by a claims assessor in respect of the claim concerned." [98]
18. As Giles JA observed in McKee v Allianz Australia Insurance Ltd, [99] "[a] key concept in Pt 3.4 is that of a matter. A medical assessment is an assessment of a medical disagreement about any of the 'matters' described in s 58. All the matters are medical in nature; there is possible enlargement so far as the degree of impairment of earning capacity requires knowledge of workplace requirements, but medical professionals frequently express opinions on impairment of earning capacity."
19. Medical disputes are determined in the first instance by a medical assessor or, on review, by a "review panel of medical assessors". [100] The purpose of setting up a panel with experts is to enable it to resolve questions within its expertise. [101] In McKee, [102] Giles JA expressed the view that although expressed in the context of the Workplace Injury Management and Workers Compensation Act 1998 (NSW), this observation in Siddik was apposite to describe the review panel carrying out functions under s 63 of the MAC Act. It is equally apposite to first instance medical assessors.
20. It might be accepted that both sub-sections 58(1)(b) and (d) refer to "the motor accident". In the first context, the issue is whether any treatment referred to in s 58(1)(a) "relates to the injury caused by the motor accident". In the second context, the question is whether "the degree of permanent impairment of the injured person as a result of the injury caused by the motor accident is greater than 10%". In each case, the question posed relates to an issue which can only arise if the issue of liability has been determined in the plaintiff's favour. As Ms Sproule submitted, the use of the definite article supports the conclusion that there is an identified "motor accident" and that the task of the medical assessor is to determine the causation issue each sub-section poses by reference to that "motor accident".
21. The conclusion I have reached is also supported by the extrinsic material to which I have earlier referred, [103] no part of which suggested that the process of medical assessment would concern the determination of liability issues.

Mills: its ancestry and progeny

1. AAMI's submission that it was for the medical assessor to determine whether the 5 July incident was a motor accident within s 3 of the MAC Act is founded on a line of authority, principally Motor Accidents Authority of NSW v Mills. [104] In my view those authorities do not support AAMI's submission.
2. The issue in Mills was whether the power in s 62(1) of the MAC Act to refer again for medical assessment under Pt 3.4 of Ch 3 could be exercised to require assessment only of the degree of permanent impairment, excluding whether the permanent impairment was as a result of an injury caused by the relevant motor accident. [105]
3. The issue arose in the following circumstances. Mr Mills was injured when a motor vehicle he was driving ran off the Wiseman's Ferry Road and came to rest in bushland. He brought proceedings in the District Court against the Nominal Defendant, claiming damages for injuries said to have been suffered in the accident. He alleged that he had run off the road when forced to take action to avoid a motor vehicle travelling in the opposite direction on the incorrect side of the road, and that after due inquiry and search the other motor vehicle could not be identified. [106] The trial judge held that the accident had occurred as Mr Mills claimed, that negligence of the driver of the other vehicle had caused it, and that there had been due inquiry and search. He concluded "that the Nominal Defendant is liable for the injury suffered by the plaintiff". [107] His Honour also held that Mr Mills' back injury was causally related to the motor vehicle accident. [108] His Honour made an order referring for further medical assessment pursuant to MAC Act, s 62 "the question of the extent of [Mr Mills'] whole impairment and not the question of whether or not that impairment (or the injury giving rise to it) was caused by the accident the subject of these proceedings". [109]
4. In a passage not essential to his conclusion, dealing with "[t]he extent of conclusiveness", Giles JA (with whom Tobias JA and Handley AJA agreed) observed that "[t]he statement of the threshold in [MAC Act,] s 131 contained the composite phrase, 'the degree of permanent impairment of the injured person as a result of the injury caused by the motor accident', with the two elements of degree of permanent impairment and of causation of the degree of permanent impairment. The same phrase with its two elements was [also] found in ss 131 [sic], 133(1) and 58(1)(d)." [110]
5. Mills was heard in March 2010. At the time the accident in Mills occurred, s 61 was in a different form to that which applied as at 5 July 2009. Section 61(2) addressed the issue of conclusivity of a medical assessor's certificate by reference to a list of matters referred to in s 58(1), including "whether the degree of permanent impairment of the injured person is greater than 10%". Section 61(3), which had been repealed by 5 July 2009, provided "[a]ny such certificate as to any other matter is evidence (but not conclusive evidence) as to the matters certified in any court proceedings or in any assessment by a claims assessor in respect of the claim concerned." There was no sub-section (10) or (11).
6. After a discussion about the fact that provisions in Pt 3.4 such as the then s 61(2)(a) used a shorter phrase, "the degree of permanent impairment", without express reference to the element of causation, Giles JA observed that "[t]hat element must, however, be read into the use of the shorter phrase." [111] This was because: "[61] … Assessment of degree of permanent impairment without regard to causation from the motor accident was not relevant to determining whether the threshold in s 131 was reached, and would depart from the description of the matter in s 58(1)(d). A medical assessment of degree of permanent impairment without regard to causation from the motor accident had no statutory basis or function. That the shorter phrase included the element of causation is clear from its use in s 132, because the point of the degree of permanent impairment was sufficiency for an award of damages for non-economic loss. It is also clear from s 133(2), because the shorter phrase related back to the composite phrase in s 133(1). [62] It was the same, in my opinion, where s 61(2)(a) and s 61(6) referred to a certificate 'as to whether the degree of permanent impairment of the injured person is greater than 10%'. This meant permanent impairment as a result of the injury caused by the motor accident. The conclusive effect of such a certificate extended to the element of causation, and the determination by the court of the degree of permanent impairment of the injured person, permitted under s 61(6), had to be assessed in accordance with s 133 which implicitly referred back to the composite phrase in s 133(1)."
7. Giles JA then observed that "[s]ection 62(2) [sic, s 61(2)] now refers to a certificate 'as to a medical assessment matter' and this conclusion is clear on the terms of the amended Act … [t]he conclusiveness of the medical assessment, as certified, included the medical assessor's finding that the permanent impairment was or was not as a result of the injury caused by the motor accident." [112]
8. In reaching his conclusion, Giles JA observed that "[t]here was strong emphasis in the [MAC Act] on leaving for assessment under Pt 3.4 whether there was the degree of permanent impairment necessary for an award of damages for non-economic loss, meaning permanent impairment as a result of the injury caused by the motor accident", a conclusion his Honour found was reinforced by the legislative history to which I have referred. [113] His Honour held that the trial judge had exceeded the power conferred by s 62 in concluding that his earlier finding that Mr Mills' back injury was caused by the motor accident, [114] meant that "whatever degree of permanent impairment would be assessed was caused by the motor accident." [115] Rather, the reference in s 62(1) to referral again of "a matter referred for assessment under this Part" picked up "the elements of causation and of degree of permanent impairment and … [i]n accordance with the scheme both elements were for the medical assessor, and the court could not decide them." The judge's finding made for the purpose of deciding that there should be referral again under s 62(1) did not bind the parties in the assessment, and he could not make an order binding on the parties to prevent the medical assessor determining the issue of causation. [116] His Honour concluded that "the degree of permanent impairment as a result of the injury caused by the motor accident (s 58(1)(d); s 131) was unequivocally for the medical assessor, including the element of causation." [117] His Honour referred, as authority for that proposition, to Pham v Shui [118] and Ackling. [119]
9. AAMI relies on the use in Mills, and authorities such as Rodger v De Gelder, [120] of the composite phrase "degree of permanent impairment as a result of the injury caused by the motor accident" to support its submission that it is for a medical assessor to determine whether an incident falls within the statutory definition of "motor accident" in s 3. However, the question whether an incident in which a claimant was injured fell within the statutory definition did not arise in either Mills or in any of the authorities to which AAMI refers.
10. In Mills, there was no issue that a "motor accident" had occurred. Rather, as I have said, the issue on liability at trial was whether the motor accident was caused by an unidentified vehicle so that proceedings could be brought against the Nominal Defendant, an issue determined in the plaintiff's favour before the issue of referral to the medical assessor arose.
11. In Rodger, [121] the plaintiff, Mr De Gelder, was injured in a motor vehicle accident when a vehicle driven by Mr Rodger collided with the rear of his stationary vehicle. There was no issue that there had been a "motor accident" within the statutory definition. The issue was as to the degree of permanent impairment suffered by Mr De Gelder in the accident. [122]
12. In Pham, the plaintiff, who was standing on the footpath, was injured when he was struck by the defendant's car as the defendant was driving from a driveway onto the footpath. The driver did not see the plaintiff before his car collided with him. [123] Once again, there was no issue that there had been a "motor accident" within the statutory definition. The issues on appeal concerned contributory negligence and damages. The latter issue turned on the ambit of the conclusionary effect of certificates given under s 61 of the MAC Act and whether medical assessments for the plaintiff were wrongly excluded.
13. At the time Pham was decided, s 61(2) was in the same form as it was in Mills and s 61(3), which had been repealed by 5 July 2009, was still in force. [124] The trial judge held that the certificates and accompanying reasons were conclusive evidence as to the degree of permanent impairment as a result of the injury caused in the motor accident and the nature of the injuries "sustained by the plaintiff in the accident". [125] Having reached that conclusion, the trial judge held that evidence contradicting the matters dealt with in the certificates and accompanying reasons was inadmissible for all purposes, including for the purpose of establishing economic loss and, accordingly, on this basis rejected a body of expert evidence the plaintiff sought to tender on the latter issue. [126]
14. On appeal, the plaintiff contended the certificates issued by the medical assessor "were no more than the gateway to damages for non-economic loss under s 131". [127] While the plaintiff conceded that evidence could not contradict the certificates in relation to non-economic loss, he argued the certificates should not have been treated as conclusionary against any compensation for his economic loss claim for domestic care. [128]
15. Santow JA held that s 61(2)(a) meant that the certificate's conclusivity applied "only to the bare conclusion that the degree of permanent impairment for that purpose was (or was not) greater than 10%". [129] In his Honour's view, that conclusion was reinforced by the structure of MAC Act, under which the "regime in Pt 5.2 is clearly a separate and distinct regime concerned with economic loss [and] operates as a parallel universe to Pt 5.3 dealing with damages for non-economic loss." [130] Accordingly, the certificate was conclusive as to the medical causation of the relevant "injury", but not as to matters outside of the strict limits of s 61(2). [131]
16. In Ackling, the plaintiff ruptured his L5/S1 disc in 2003 when he was thrown off the rear of the tray of a truck being driven across a paddock onto the ground. About a year later he exacerbated the injury while doing road repair work. After the exacerbating incident, he was diagnosed with a psychiatric injury which he claimed was caused by the motor accident. There was a dispute as to the degree of permanent impairment the plaintiff suffered as a result of his psychiatric injury which was referred to a medical assessor. The assessor's certificate stated "NIL diagnose psychiatric disorder related to the motor accident." [132] A review panel affirmed that conclusion, determining that the first accident was not a cause of, or a significant contributing factor to, the plaintiff's psychiatric disorder. [133]
17. The plaintiff commenced judicial review proceedings pursuant to s 69 of the Supreme Court Act 1970 (NSW), seeking orders setting aside the certificates and statements of reasons of the medical assessor and the review panel. It was common ground that each decision-maker had erred in law in the test of causation. [134] The principal issue was whether it was within the jurisdiction of the review panel to determine whether the relevant impairment of the plaintiff was as a result of an injury "caused by the [2003] motor accident". [135] However, as in other cases, the use of the composite phrase conceals rather than reveals the true issue. There was no issue that the 2003 accident constituted a "motor accident" within the statutory definition. The issue was whether s 58(1)(d) empowered a medical assessor to determine causation. [136]
18. In Spratt v Perilya Broken Hill Ltd; Spratt v Rowe, [137] Leeming JA said, referring to Rodger, that the proposition "that the degree of permanent impairment as a result of the injury caused by the motor accident (s 58(1)(d); s 131) is unequivocally for the medical assessor, or review panel, as the case may be, including the element of causation" should be "regarded as settled law, [and] flows directly from the text of s 58(1)(d) and s 131". That statement may initially be thought to give AAMI some support. However as is apparent from the foregoing analysis and his Honour's consideration of Mills, that is a false hope. Rather, as his Honour explained in Spratt, [138] "the ratio of Mills is that the [MAC Act] leaves, for the exclusive and conclusive determination by medical assessors, questions of permanent impairment and causation". As is plain, his Honour did not consider that Mills held that s 58(1)(d) left the issue of what constitutes, or what can be or characterised as, a "motor accident" for the medical assessor.

Reprise: the medical assessment

1. It was not, accordingly, incumbent upon Assessor Reutens to determine whether the series of incidents AAMI contended occurred on 5 July 2009 and led to Ms Sproule's injuries constituted a "motor accident" within s 3 of the MAC Act. That was a question which had to be determined by a court, as AAMI seemed to accept at the time it had Ms Sproule's matter exempted from the assessment process pursuant to s 92(1)(a).
2. A matter should not be referred to a medical assessor where there is any doubt about the issue of whether the events which occurred fell within the statutory definition. That liability issue should be determined before a medical assessor is asked to determine the s 58(1)(d), or, it might be observed, the s 58(1)(b), issue. The medical assessor can then "take note of the court's reasons". [139]
3. If, however, in a matter referred to a medical assessor, it is apparent that doubt about whether an incident falls within the statutory definition exists, the medical assessor should make findings about causation by reference to the physical event or events, and leave it to the court to determine whether or not the events constitute a "motor accident". [140]
4. AAMI's submissions on the s 58(1)(d) referral which formed part of the material before Assessor Reutens raised the issue "whether the claimant was injured as a result of a motor accident or as a result of the assaults perpetrated by Judd Ball". [141] To the extent the submissions sought to break the 5 July incident down, they referred expressly to that part in which Mr Ball reversed the vehicle towards Ms Sproule. AAMI accepted in this Court that that part of the incident constitutes a "motor accident".
5. AAMI did not ask Assessor Reutens merely to make findings in the manner I have indicated. Notwithstanding that omission, in my view Assessor Reutens undertook her task with a view squarely to determine whether either the assaults or the "motor accident" which she described as "the car reversing into [Ms Sproule]" caused her PTSD, major depression and panic attacks. She expressly made her causation finding by reference to "the accident" which she found to be a "substantial cause" of Ms Sproule's mental state. In reaching that conclusion, it is apparent Assessor Reutens applied the instructions on causation in the Permanent Impairment Guidelines which instructed that "[t]he motor accident does not have to be a sole cause as long as it is a contributing cause, which is more than negligible".

Permanent Impairment Guidelines and causation

1. AAMI relied on the fact that the cll 1.7 - 1.9 of the Permanent Impairment Guidelines informed the manner in which medical assessors determined issues of causation, including by directing their attention to common law principles of causation, to support its submission that as a medical assessor was required to apply legal principles, it could be taken that determining whether an incident constituted a "motor accident" was within the purview of a medical assessment matter in s 58(1)(d).
2. This submission faces several difficulties, of which the most obvious one is that cll 1.7 - 1.9 of the Permanent Impairment Guidelines are directed to informing the medical assessor how to determine the cause of injury in a damages context, not a liability one.
3. Secondly, the causation "test" set out in the Permanent Impairment Guidelines cannot inform the question of causation in the liability context. That question, as I have said, is governed by the s 5D test for causation in the Civil Liability Act.
4. Thirdly, the Permanent Impairment Guidelines cannot determine the proper construction of the MAC Act. Indeed, a guideline, or an obligation imposed upon a medical assessor to comply with a guideline, which purported to contradict an obligation imposed by the MAC Act would likely be ultra vires to the extent it purported to do so. [142] Caution should be exercised, in my view, in considering whether those guidelines can inform the exercise the medical assessor was required to undertake.

Discretionary disposition

1. In the circumstances, it is unnecessary to deal other than briefly with AAMI's complaint about the primary judge's alternative discretionary disposition of the matter. AAMI accepted that such a discretion was available "if a more convenient and satisfactory remedy exists", [143] but submitted it should not be exercised lightly. [144]
2. The bases upon which the matter could have been referred again for assessment are limited as set out in s 61(4) and (5) to which the primary judge did not refer. It is sufficient to note those provisions without finally deciding this issue, in the light of my conclusion on the substantive issues.

Conclusion

1. The Proper Officer's role in determining the review application pursuant to s 63 of the MAC Act is that of a gatekeeper, not a decision-maker. [145] The power is engaged when the Proper Officer is satisfied that "there is reasonable cause to suspect" that the medical assessment was incorrect in a material respect. [146] It might be accepted, as AAMI submits, that this is a low threshold. I am not persuaded however, that the primary judge erred in rejecting AAMI's submission that the Proper Officer should have found it had been crossed. His Honour correctly held that it was not the function of a medical assessor to determine what constituted a "motor accident".
2. On AAMI's submissions, the tail of one head of damages for non-economic loss would wag the dog of the critical, and primary, issue of liability which arises in a motor accident claim before the question of any award of damages. To accept that submission would give the MAC Act a construction which, in my view, would be manifestly absurd or unreasonable.

Orders

1. I propose the following orders: 1. Grant leave to appeal. 2. AAMI to file the notice of appeal a draft of which appears in the White Book within seven days. 3. Appeal dismissed with costs.
2. MACFARLAN JA: I agree with the judgments of McColl and Simpson JJA.
3. SIMPSON JA: The central issue sought to be raised in these proceedings involves a relatively short point: what is encompassed in the obligation of a medical assessor, appointed under Pt 3.4 of Ch 3 of the Motor Accidents Compensation Act 1999 (NSW) ("the MAC Act") to assess whether the degree of permanent impairment of an injured person caused by a motor vehicle accident is greater than 10 per cent?
4. The relevant legislation is set out in the judgment of McColl JA, which I have had the advantage of reading in draft. I do not propose to repeat the legislative provisions.
5. The point arises in the following way (stated as shortly as possible). On 5 July 2009 Ms Vanessa Sproule was involved in an event (or series of events) that, she claimed, caused her permanent psychiatric injury. The clearest factual account of the events is contained in a statement subsequently made by Ms Sproule to police. She asserted that, prior to 5 July 2009, she and a Mr Judd Ball had been in a relationship that terminated in 2006. In circumstances it is unnecessary to recount in detail, in the early hours of 5 July Ms Sproule was driving her motor vehicle with Mr Ball as passenger, when Mr Ball violently assaulted her, to the point that she briefly lost consciousness. The assaults continued after she regained consciousness, and she attempted to alight from the vehicle, eventually falling to the ground. Mr Ball took control of the car and drove off. Ms Sproule took shelter near a small brick fence, and attempted to obtain assistance by telephoning the emergency number. Mr Ball reversed the car directly towards her, alighted from the car, and again physically assaulted her. While Mr Ball was out of the car, Ms Sproule re-entered it, on the passenger side, and locked the doors. Before she could close the window, Mr Ball reached in, unlocked the door and resumed the assaults. He dragged Ms Sproule out of the car, continually assaulting her. He forced her into the passenger side of the vehicle. At this time, she was partly in, partly out, of the vehicle. To avoid the assaults, she pulled herself in and closed the door. Mr Ball re-entered the car, took the driver's seat, and drove off at high speed. He threatened to crash the car, and to drive in such a way as to kill both of them. Eventually he brought the car to a halt outside a block of home units and Ms Sproule left the vehicle. He then drove the car into an underground car park. After a little time he approached Ms Sproule, pushed her, and demanded that she come inside the units to talk. She attempted to call police; he took the phone and threw it against a brick wall.
6. Ms Sproule made a claim for damages for personal injury. The claim was governed by the MAC Act. She claimed to be suffering from post-traumatic stress disorder as a consequence of the events. She provided supporting medical reports and information.
7. In order to succeed in her claim, it was necessary that Ms Sproule establish that her injury was: "… caused by the fault of the owner or driver of [the vehicle] in the use or operation of the vehicle [and that] the … injury [was] a result of and [was] caused … during: (a) the driving of the vehicle, (b) … or (c) … or (d) a dangerous situation caused by the driving of the vehicle …" [MAC Act, s 3A(1)] The language of s 3A(1) is almost identical with that part of s 3 which defines "motor accident" as an "incident or accident involving the use or operation of a motor vehicle" with the same features as are referred to in s 3A(1).
8. It is apparent, from the account above, that part of the events took place while both Ms Sproule and Mr Ball were in the vehicle; part involved Mr Ball reversing the vehicle towards Ms Sproule; and part took place while both parties were outside the vehicle, although in its near vicinity.
9. Ms Sproule's claim was (or involved) a claim for damages for non-economic loss. It was therefore necessary that she show that she suffered a degree of permanent impairment greater than 10 per cent: MAC Act, s 131.
10. The insurer, AAMI, filed a Reply to Ms Sproule's claim. The substance of the Reply was: "The Insurer does not concede that the injuries alleged by the claimant were sustained in a 'motor accident' nor that any alleged injuries result in permanent impairment exceeding 10%."
11. In support of the Reply, AAMI provided written submissions. The salient passages in the written submissions are: "3 The assessment of permanent impairment is complicated due to two primary factors. Firstly, AAMI notes that the claimant was involved in a prior motor vehicle accident on 7 May 2006 in which she sustained similar injuries to those now complained of (R3). Secondly, AAMI submits that there [are] serious questions as to whether the claimant was injured as a result of a motor accident or as a result of the assaults perpetrated by Judd Ball. 4 The medical certificate attached to the Personal Injury Claim Form (A1) completed by Dr Boddy. In response to the questions 'Are the injuries or conditions consistent with the circumstances of the motor accident described to you?' the doctor has marked 'No' and has written in brackets 'assault'. Further, the diagnosis or description of injury is 'blunt trauma secondary to alleged assault'. … 13 When the various versions are considered together it is evident that the claimant was not in fact injured as a result of the motor accident. One cannot be confident that, absent independent corroboration, what the claimant says at a given time about past events is what actually happened. Clearly, it is doubtful that the claimant was in fact hit by the vehicle on the night of the assault or that it was in fact involved in an accident. … 26 AAMI submits that the claimant was not injured as a result of a motor accident and that even if she was, no permanent impairment results. Further, if she suffers any permanent impairment, it is not the result of the incidents she presently relies upon." (italics added)
12. The claim was referred, under s 58 of the MAC Act, to a medical assessor, Dr Sharon Reutens. Dr Reutens issued a certificate on 15 August 2012. The question to which Dr Reutens directed her attention was: "Whether the degree of permanent impairment of the injured person as a result of injury caused by the motor accident is greater than 10%." She noted the injury the subject of assessment to be: "Head - PTSD"
13. Dr Reutens concluded that Ms Sproule suffered a whole person impairment of 17 per cent, of which 5 per cent was attributable to a previous injury. After adjustment for the effects of treatment the assessment of "final permanent impairment" was 14 per cent.
14. Pursuant to s 63 of the MAC Act, AAMI sought review of Dr Reutens' medical assessment. By sub-s (3) of s 63 such an application is made to "the proper officer" of the Motor Accidents Authority (now the State Insurance Regulatory Authority), who is to arrange for any such application to be referred to a panel of at least three medical assessors: "…but only if the proper officer is satisfied that there is reasonable cause to suspect that the medical assessment was incorrect in a material respect having regard to the particulars set out in the application."
15. AAMI's application contained the following. In answer to a question "what is the error or mistake? [said to have been made by the medical assessor]", AAMI inserted: "1 The Assessor has failed to distinguish and apportion between the various assaults alleged by the claimant against Mr Ball and the effect of what she describes as 'The motor vehicle accident (the car reversing into her) …'"
16. In answer to a question "How is this material to the outcome of the assessment?", AAMI inserted: "Leaving aside for the moment, the question of apportionment between the motor accidents matters and the assaults that have nothing to do with the motor accident, had Assessor Reutens correctly classified the various categories under the PIRS [Psychiatric Impairment Rating Scale], the following would have resulted: … In addition, AAMI submits that while Assessor Reutens' apportionment between the 2006 accident and the 2009 incidents, in relation to the 2009 incidents she failed to make any or any proper attempt to disentangle the consequences of the non-motor accident assaults described in her report and their consequences which she has, in effect, inappropriately lumped together as the 2009 motor accident. … Having identified more than one cause for the claimant's current problems, some arguably motor accidents but many clearly not, AAMI contends that Assessor Reutens has failed to apportion her permanent impairment assessment between what is compensable under the Act and what is not. That failure is a material error and taken alone or in combination with her incorrect classification of the PIRS categories referred to above will surely see the assessment fall below 10%." (italics in original)
17. The proper officer refused the application for review, declaring himself: "… not satisfied that there is reasonable cause to suspect that the medical assessment is incorrect in a material respect." In the body of his statement of reasons, the proper officer said: "5 The applicant [AAMI] submits that the medical assessment is incorrect in the following respect/s: � Failure to apportion � Incorrect classification under the psychiatric impairment rating scale" 6 The applicant says in relation to the 2009 incidents [the assessor] failed to make any or any proper attempt to disentangle the consequences of the non-motor assaults … It is therefore submitted that the assessor failed to apportion the impairment assessment between what is compensable under the Act and what is not."
18. Under "Reasons for Decision", the proper officer said: "8 Whether or not the alleged 'incidents' which took place in July 2009 constitute a 'motor accident' is not, in my view, a matter for the assessor to determine. It is a matter that the CARS assessor or a court will determine in due course as indicated in the CARS Preliminary Conference Report of CARS Assessor Harvey dated 10 October 2012. 9 Even if I am wrong here, there is no suggestion in the applicant's submissions on how the assessor could have apportioned the alleged incidents which all occurred on the same day within minutes of each other. The apportionment provisions in the MAA Guidelines … are clear. They require objective evidence of a pre-existing symptomatic permanent impairment or a pre-existing psychiatric diagnosis or condition. As indicated by the assessor, she was able to apportion between the 2006 accident and the 2009 accident but there is nothing to suggest the psychiatric impairment within the 2009 accident/incidents could be apportioned."
19. By Summons filed in the Supreme Court AAMI sought judicial review of the decision of the proper officer, asserting jurisdictional error or error on the face of the record (Supreme Court Act 1970 (NSW), s 69). On 10 July 2015 Button J dismissed the Summons: AAI Limited v Motor Accidents Authority of New South Wales [2015] NSWSC 912. It is against that judgment that AAMI now seeks leave to appeal. In its submissions to the medical assessor (Dr Reutens), AAMI did not argue that, in performing her functions as a medical assessor, she ought to attempt to "disentangle" the effects of those parts of the events of 5 July that took place in the motor vehicle, or involving it, and those that took place while both Ms Sproule and Mr Ball were out of the vehicle. That, however, was the proposition that AAMI put to the proper officer, to Button J, and to this Court.
20. Before Button J and before this Court, AAMI asserted constructive jurisdictional error on the part of the proper officer: (i) in failing to ask whether Dr Reutens' assessment was incorrect in a material respect by reason of her asserted failure to determine whether Ms Sproule's injury was caused by a motor accident; and (ii) failing to ask whether Dr Reutens was incorrect in a material respect by reason of non-compliance with the statutory duty to determine whether Ms Sproule's injury was caused by a motor accident. The focus of the argument lies in the words "caused by the motor accident".
21. The MAC Act does not itself confer a right of action in respect of injury (or death) caused by motor vehicle accidents. Its long title ("An Act to establish a new scheme of compulsory third-party insurance and payment of compensation relating to the death of or injury to persons as a consequence of motor accidents …") indicates that its purpose is to regulate the award of damages in respect of common law claims arising out of motor vehicle accidents. That regulation includes a process of medical assessment (Pt 3.4 of Ch 3), and a process of (non-judicial) claims assessment (Pt 4.4 of Ch 3).
22. So far as I can see, for present purposes the two questions posed in the application for leave to appeal are essentially identical. They raise the issue whether the task committed to Dr Reutens as medical assessor required her to determine the extent to which Ms Sproule's psychiatric condition was attributable to those parts of the events of 5 July 2009 that took place in, or involved, the motor vehicle, and those that took place outside. For that purpose, counsel for AAMI sought to divide the events of 5 July into five "phases". As pointed out above, that is not the way AAMI advanced its case before Dr Reutens.
23. Some superficial support for AAMI's position may be obtained from s 58, pursuant to which the medical assessment procedures apply to whether any treatment given to the claimant "relates to the injury caused by the motor accident".
24. However, it is clear that the legislation does not contemplate dissection of "the injury" into portions. "Permanent Impairment Guidelines" issued under s 44 of the MAC Act expressly recognise that there will, on occasions, be a need to distinguish between the medical consequences of a motor accident, and any pre-existing impairment "in the same region", and provide for appropriate apportionment. No corresponding provision is made for the apportionment of the consequences of a discrete incident in a single event.
25. As indicated above, Pt 4.4 of the MAC Act contains detailed provisions for the assessment and resolution of claims. These are distinct from the provisions in Pt 3.4, which provides for medical assessment (of motor accident injuries). Section 92 specifically provides for exemption from assessment under Pt 4.4 in respect of claims: (a) that are exempt under Motor Accidents Claims Assessment Guidelines [issued under s 69] or the Regulations; or (b) claims determined by a claims assessor to be unsuitable for assessment under Pt 4.4.
26. As sub-s (2) makes plain, exemption from the assessment procedures permits the claim to be determined by judicial process. This is the process, in my opinion, by which any "disentangling" of the effects of the motor accident on Ms Sproule as distinct from the assaults should be determined.
27. I specifically agree with the reasoning of McColl JA in [133]-[140].
28. In my opinion, no error, jurisdictional or otherwise, has been identified on the part of the proper officer, and Button J was correct in the conclusion that he reached.
29. I agree with the orders proposed by McColl JA.

Endnotes

1. The first and second respondents filed submitting appearances.
2. AAI Limited v Motor Accidents Authority of New South Wales [2015] NSWSC 912.
3. Supreme Court Act 1970 (NSW), s 101(2)(r).
4. Cf Uniform Civil Procedure Rules 2005 (NSW) (UCPR) 51.22.
5. The definitions of "injury", "motor accident" and s 3A were inserted by the Motor Accidents Compensation Amendment Act 2006 (NSW) which relevantly commenced on 1 October 2006.
6. Amendments made by the Motor Accidents Compensation Amendment Act 2010 (NSW), Sch 1[3] to s 3A(1) of the MAC Act by the insertion of sub-s (d) (and a corresponding amendment to the definition of "motor accident" in s 3) which amendments relevantly extend to an incident or accident that occurred on or after 1 October 2006 (Sch 5, Pt 9, cl 38) retrospectively broadened the scope of the MAC Act (Bayon v Bayon (2014) 69 MVR 360; [2014] NSWCA 434 (Bayon) (at [7]) per Basten JA (Meagher JA agreeing)) but not in a manner either party suggested was germane to this case.
7. MAC Act, s 3B(1).
8. Ibid, s 5(1)(b).
9. Ibid, s 43.
10. Ibid, s 44(1)(c).
11. Ibid, s 44(6).
12. Ibid, s 44(1)(c); see Motor Accidents Authority of New South Wales, Permanent Impairment Guidelines (1 October 2007).
13. Ibid, s 44(1)(d); see Motor Accidents Authority of New South Wales, Medical Assessment Guidelines (11 July 2008).
14. Ibid, s 57A.
15. Ibid, s 59(1).
16. Ibid, s 60.
17. Ibid, s 65(1).
18. Ibid, s 67(1).
19. Ibid, s 72(1).
20. Ibid, s 80(1).
21. Ibid, s 81(1).
22. Ibid, s 83(2).
23. Ibid, s 89(1).
24. Ibid, s 98.
25. Ibid, s 99.
26. Ibid, s 99A(1).
27. Ibid, s 89E(a) and (c).
28. Ibid, s 90.
29. Ibid, s 108(1)(a).
30. Ibid, s 92(1)(a).
31. Ibid, s 92(1)(b).
32. Ibid, s 69(3).
33. Motor Accidents Authority of New South Wales, Claims Assessment Guidelines (11 July 2008).
34. PCA is the Principal Claims Assessor appointed pursuant to MAC Act, s 99A.
35. MAC Act, s 94A(1).
36. Ibid, s 94A(3)(a) and (d).
37. Ibid, s 95(1).
38. Ibid, s 95(2).
39. Ibid, s 96(1)(a1).
40. Ibid, s 100.
41. Ibid, s 101.
42. See generally s 104.
43. MAC Act, s 107.
44. Ibid, s 110(1).
45. Ibid, s 111(1) and (2). Section 111(3) explains what constitutes "significant evidence".
46. Ibid, s 122(1).
47. Ibid, s 122(3).
48. Ibid, s 123.
49. Subject to indexation pursuant to s 146.
50. MAC Act, s 126(1).
51. Ibid, s 131.
52. Explanatory Memorandum to the Bill which became the MAC Act (Explanatory Memorandum).
53. New South Wales Legislative Council, Parliamentary Debates (Hansard), 3 June 1999.
54. While the Explanatory Memorandum and the Second Reading Speech may be used for the purposes for which s 34 of the Interpretation Act 1987 (NSW) provides, they cannot supplant the words of the MAC Act: Whitfield v Melenewycz (2016) 77 MVR 420; [2016] NSWCA 235 (at [20]) per Meagher JA (Simpson JA and Sackville AJA agreeing).
55. "AMA 4 Guides" is a reference to the American Medical Association publication "Guides to the Evaluation of Permanent Impairment", 4th Edition, 3rd Printing (1995): cl 1.2.
56. Clause 1.3 provides that "[t]he convention used in these MAA Guidelines is that if the text is in bold, it is a directive as to how the assessment should be performed." No part of the MAA Guidelines upon which AAMI relies is in bold.
57. Medical Assessment Guidelines, cl 11.1.
58. Motor Accidents Authority of NSW v Mills (2010) 78 NSWLR 125; [2010] NSWCA 82 (at [80]) per Giles JA (Tobias JA and Handley AJA agreeing).
59. AAMI accepts that that aspect of the 5 July 2009 incident constituted by the "car reversing into" Ms Sproule referred to in Dr Reuten's reasons constitutes a motor vehicle accident within the meaning of the MAC Act.
60. Gates v City Mutual Life Assurance Society Limited (1986) 160 CLR 1; [1986] HCA 3.
61. The 14% finding entitled Ms Sproule to damages for non-economic loss: MAC Act, s 131.
62. (at [12]).
63. (at [78]) (paragraph commencing "The history is consistent with a worsening of Ms Sproule's mental state …").
64. See [35].
65. Primary judgment (at [2]).
66. Ibid (at [33]).
67. Ibid (at [40] - [41]).
68. Referring to Meeuwissen v Boden (2010) 78 NSWLR 143; [2010] NSWCA 253 (Meeuwissen).
69. Referring to Ackling v QBE Insurance (Australia) Limited (2009) 75 NSWLR 482; [2009] NSWSC 881 (Ackling) and Allianz Australia Insurance Ltd v Girgis (2011) 59 MVR 548; [2011] NSWSC 1424.
70. The reference to Gonzales, was to Allianz Australia Insurance Ltd v Gonzales [2013] NSWSC 362.
71. Primary judgment (at [55]).
72. Primary judgment (at [56]).
73. Cf R v Commonwealth Court of Conciliation and Arbitration; Ex parte Ozone Theatres (Aust) Ltd (1949) 78 CLR 389 (at 400); [1949] HCA 33; Re Refugee Review Tribunal; Ex parte Aala (2000) 204 CLR 82; [2000] HCA 57 (Aala) (at [56]).

74. See [86] above.
75. Alcan (NT) Alumina Pty Ltd v Commissioner of Territory Revenue (Northern Territory) (2009) 239 CLR 27; [2009] HCA 41 (at [47]) per Hayne, Heydon, Crennan and Kiefel JJ; Military Rehabilitation and Compensation Commission v May (2016) 90 ALJR 626; [2016] HCA 19 (at [10]) per French CJ, Kiefel, Nettle and Gordon JJ; Smalley v Motor Accident Authority of New South Wales (2013) 85 NSWLR 580; [2013] NSWCA 318 (at [43] - [45]; [48]) per Leeming JA (Meagher and Barrett JJA agreeing).
76. Project Blue Sky Inc v Australian Broadcasting Authority (1998) 194 CLR 355; [1998] HCA 28 (Project Blue Sky) (at [69]) per McHugh, Gummow, Kirby and Hayne JJ.
77. Ibid, referring, among other cases, to Commissioner for Railways (NSW) v Agalianos (1955) 92 CLR 390 (at 397); [1955] HCA 27 per Dixon CJ.
78. Allianz Australia Insurance Ltd v GSF Australia Pty Ltd (2005) 221 CLR 568; [2005] HCA 26 (at [43]) per McHugh J.
79. Nominal Defendant v Gabriel (2007) 71 NSWLR 150; [2007] NSWCA 52 (Gabriel) (at [48]) per Campbell JA (Hodgson JA agreeing).
80. It is, of course, in the first instance, a matter for the insurer to advise a claimant of its position on liability pursuant to s 81.
81. Gabriel (at [48], [53], [65] - [66]) per Campbell JA (Hodgson JA agreeing).
82. MAC Act, s 94(1)(b).
83. Gabriel (at [53]).
84. MAC Act, s 132(1).
85. MAC Act, s 43(1); s 67(1) and s 122(1) respectively.
86. R v Khazaal (2012) 246 CLR 601; [2012] HCA 26 (at [31]) per French CJ.
87. Axiak v Ingram (2012) 82 NSWLR 36; [2012] NSWCA 311 (Axiak) (at [60]) per Tobias AJA (Beazley JA and Sackville AJA agreeing) (application for special leave to appeal refused: Ingram v Axiak [2013] HCATrans 64).
88. Second Reading Speech, Motor Accidents Compensation Amendment Bill, New South Wales Legislative Assembly, Parliamentary Debates (Hansard), 9 March 2006 (at 21404).
89. Civil Liability Act, s 3B(2), s 5A; Bayon (at [8]).
90. Gabriel (at [41]) per Basten JA; Smalley (at [58]).
91. Leach v The Nominal Defendant (QBE Insurance (Australia) Ltd) (2014) 67 MVR 494; [2014] NSWCA 257 (at [68]) per McColl JA (Gleeson JA and Sackville AJA agreeing); see also (at [82]) per Sackville AJA. The plaintiff must establish that "the negligence was a necessary condition of the occurrence of the harm" (s 5D(1)(a), Civil Liability Act) and, if negligence is identified, whether "it is appropriate for the scope of the negligent person's liability to extend to the harm so caused" (s 5D(1)(b) Civil Liability Act): Bayon (at [19]) per Basten JA; (at [43]) per Adamson J (Meagher JA agreeing).
92. MAC Act, s 61(2).
93. Ibid, s 92(1)(a).
94. Claims Assessment Guidelines, cll 8.11.1 and 8.11.5.
95. See MAC Act, s 3, definition of "claim" and s 67(1), s 72, s 90, s 107.
96. MAC Act, s 3B(1)(a).
97. Ibid, s 60(1).
98. Ibid, s 61(2).
99. (2008) 71 NSWLR 609; [2008] NSWCA 163 (McKee) (at [24]) (Allsop P agreeing) (emphasis added).
100. MAC Act, s 63(1).
101. Siddik v WorkCover Authority of NSW (2008) 6 DDCR 228; [2008] NSWCA 116 (at [98]); referring to Kalil v Bray [1977] 1 NSWLR 256 (at 262) per Street CJ (Moffitt P and Glass JA agreeing).
102. (at [31]).
103. Interpretation Act, s 34.
104. (2010) 78 NSWLR 125; [2010] NSWCA 82 (Mills).
105. Ibid (at [1]).
106. Ibid (at [4]).
107. Ibid (at [12]).
108. Ibid (at [15]).
109. Ibid (at [25]).
110. Ibid (at [59]).
111. Ibid (at [60] - [61]).
112. Ibid (at [63]).
113. Ibid (at [70]).
114. See Mills (at [25]).
115. Ibid (at [73] - [74]).
116. Ibid (at [74]).
117. Ibid (at [79]) (emphasis in original).
118. (2006) 47 MVR 231; [2006] NSWCA 373 (Pham) (at [96]).
119. (at [77] - [79]). Like Mills, both Pham and Ackling involved motor accidents which occurred prior to amendments to the MAC Act by the Motor Accidents Compensation Amendment (Claims and Dispute Resolution) Act 2007 (which commenced on 1 October 2008).
120. (2015) 71 MVR 514; [2015] NSWCA 211 (Rodger).
121. Ibid (at [17]).
122. Ibid (at [2]).
123. Pham (at [1]).
124. Section 61(3) provided "Any such certificate as to any other matter is evidence (but not conclusive evidence) as to the matters certified in any court proceedings or in any assessment by a claims assessor in respect of the claim concerned."
125. Pham (at [75]).
126. Pham (at [77] - [78]).
127. Ibid (at [76]).
128. Ibid (at [79]).
129. Ibid (at [90]); the purpose was whether, within s 131 of the MAC Act, damages could be awarded for non-economic loss: ibid.
130. Ibid (at [93]).
131. Ibid (at [96]).
132. Ackland (at [7] - [10]).
133. Ibid (at [17] - [18]).
134. Ibid (at [22] - [24]).
135. Ibid (at [27]).
136. Ibid (at [49] - [53]) (plaintiff's submissions); (at [55] - [61]) (insurer's submissions); (at [67] - [70]) (Authority's submissions); reasons (at [82]; [84] - [87]).
137. (2016) 77 MVR 206; [2016] NSWCA 192 (Spratt) (at [41]) (McColl and Gleeson JJA agreeing).
138. (at [46]).
139. Mills (at [80]).
140. Cf Nominal Defendant v Hawkins (2011) 58 MVR 362; [2011] NSWCA 93.
141. See [70] above.
142. Spratt (at [51]).
143. Aala (at [56]), referring to R v Commonwealth Court of Conciliation and Arbitration; Ex parte Ozone Theatres (Aust) Ltd.
144. See Corporation of the City of Enfield v Development Assessment Commission (2000) 199 CLR 135; [2000] HCA 5 (at [56]) per Gaudron J.
145. Meeuwissen (at [23]) per Basten JA (Beazley JA and Sackville AJA agreeing).
146. Ibid (at [22]). DISCLAIMER - Every effort has been made to comply with suppression orders or statutory provisions prohibiting publication that may apply to this judgment or decision. The onus remains on any person using material in the judgment or decision to ensure that the intended use of that material does not breach any such order or provision. Further enquiries may be directed to the Registry of the Court or Tribunal in which it was generated. Decision last updated: 21 December 2016