Allianz Australia Insurance Limited v Mackenzie & Ors

Judgment 1HIS HONOUR: Nature of proceedings The plaintiff moves by an Amended Summons filed in Court on 18 December 2013 (the original Summons having been filed 27 August 2013) and relies on affidavits of Peter Utiger, solicitor, sworn 14 October 2013. Attached to Mr Utiger's affidavit was a substantial bundle of exhibits contained in two folders. 2The proceedings invoke the Supreme Court's supervisory jurisdiction, pursuant to s69 of the Supreme Court Act 1970. The plaintiff is a New South Wales compulsory third party insurer. The first defendant is a claimant under the Motor Accident Compensation Act 1999 (MAC Act) who has lodged a claim for compensation with the plaintiff as a result of a motor vehicle accident. The second defendant is the Motor Accident Authority (MAA) which administers the third party insurance and compensation scheme under the MAC Act. The third defendant is the Review Panel comprising three medical experts whose decision is under challenge. 3The decision under challenge is that of the third defendant of 22 July 2013. Section 63(3A) MAC Act provides: "(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." Accordingly, any Review Panel must re-hear a medical assessor's determination afresh, on all issues and all grounds and any Review Panel determination is capable of completely replacing the original medical assessment certificate. 4The second and third defendants have filed submitting appearances. The plaintiff and the first defendant are the only active contradictors in the matter. 5The relief claimed in the Amended Summons is: (i) An order in the nature of certiorari, or a declaration setting aside or declaring invalid the decision of the Review Panel and/or the certificate issued by it on 22 July 2013. (ii) An order in the nature of prohibition or alternatively an injunction preventing the defendants taking any further step in reliance upon the decision. (iii) An order in the nature of mandamus remitting the matter to a differently constituted Review Panel for determination according to law. 6The grounds of judicial review relied upon by the plaintiff can be summarised as follows: (a) The Review Panel wrongly stated and applied the test of causation. (b) There was error on the face of the record in that the reasons of the Review Panel were inadequate. (c) The Review Panel failed to take into account relevant considerations. Factual background 7The first defendant claimed that on 27 October 2005 when driving home as the sole occupant of a utility vehicle, a collision occurred when another vehicle failed to stop at a give way sign on his right and impacted the driver's side of his vehicle. The first defendant said that his vehicle then spun through 180 degrees as a result of the impact, finally coming to rest against the kerb. The first defendant said that he was wearing his seatbelt at the time. 8The first defendant said that he was immediately aware of low back pain but walked or was driven (he did not recall) the short distance home after police and other accident formalities were concluded at the accident site. He said that his sleep was disturbed due to pain throughout the night of the collision and he attended West Wyalong Hospital early next morning, by then complaining of right shoulder and right elbow pain, in addition to continuing low back pain. 9The first defendant said that since the collision he had continued to experience right shoulder and low back pain. He underwent a surgical procedure in relation to his right shoulder in October 2007. He underwent a spinal fusion on 21 December 2009. 10The plaintiff denied that there was a causal connection between the accident and the surgical procedures carried out in relation to the right shoulder and low back. In doing so, it relied upon the history of complaint, medical opinion and lay evidence in the form of observations made of the first defendant, which were recorded on four DVDs. 11Because of this medical dispute the first defendant's claim was referred for medical assessment by the Medical Assessment Service (MAS) pursuant to Pt 3.4 of the MAC Act. 12On 3 July 2008 Assessor Wilkins assessed the first defendant to suffer not greater than 10 percent whole person impairment (WPI) from injuries sustained in the motor vehicle accident. Assessor Wilkins found that although the first defendant had suffered injuries to his right shoulder and low back in the motor vehicle accident, the effects of those injuries had resolved by the time of the assessment. 13The matter was referred for further medical assessment by the MAS. On 16 August 2010 Assessor Oates assessed the first defendant to suffer not greater than 10 percent WPI from injuries sustained in the accident. Specifically, Assessor Oates concluded that the first defendant had suffered temporary exacerbation of degenerative changes in his right shoulder and low back, the effects of which had resolved. He found that the subsequent deterioration in the condition of both the right shoulder and the low back was not related to the motor vehicle accident. 14On 4 December 2012 the MAA advised that a further medical assessment of the first defendant would take place. On 13 March 2013 Assessor Thompson assessed the first defendant to suffer greater than 10 percent WPI as a result of injuries sustained in the accident. He found that the injuries to the right shoulder and lumbar spine were caused by the motor vehicle accident and assessed the first defendant as having suffered 28 percent WPI. 15The plaintiff applied for a review of that medical assessment by a Review Panel. On 16 May 2013 the MAA advised that the plaintiff's application for review had been successful and that the matter would be referred to a Review Panel. 16On 10 July 2013 the Review Panel assessed the first defendant as suffering greater than 10 percent WPI from injuries sustained in the accident. In order to understand the competing submissions, it is necessary to set out in some detail the content of the Review Panel certificate. 17The Review Panel certificate identified the question for consideration as: "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 percent." The importance of this assessment was that the first defendant would not have a claim for damages for non-economic loss unless his degree of WPI caused by the motor accident was greater than 10 percent. 18The Review Panel confirmed that it had received and considered the plaintiff's application form seeking a review and attached documents, together with all of the material which had been provided to Assessor Thompson. These documents included the reasons for assessment of Assessors Wilkins, Oates and Thompson. Having considered that material, the Review Panel decided that because the issue was essentially one of causation, it could be adequately decided through a consideration of the extensive documentation without any need to re-examine the first defendant. 19The Review Panel considered the injury to the right shoulder first. It recorded the history of how the accident occurred and the initial complaints of the first defendant. It noted the content of contemporaneous medical records, such as the discharge summary from the West Wyalong Hospital, together with the medical records from the West Wyalong Medical Centre which he had attended shortly after the accident. The Review Panel then recorded the content of medical reports relating to the first defendant's right shoulder which had been provided to it. The Review Panel made specific reference to four DVDs of surveillance carried out of the first defendant between April and October 2007 which showed him using his right shoulder. The Review Panel recorded the differing opinions of medical practitioners as to the significance of the surveillance material, e.g. on the one hand that it was not inconsistent with any pathology and on the other, that it was totally inconsistent with any significant shoulder pathology. 20The Review Panel expressed its conclusions in relation to the right shoulder as follows: "The Panel considered all this evidence, particularly with regards to the question of whether the claimant sustained an injury to the right shoulder which was causally related to the subject motor accident. Although the contemporaneous evidence was somewhat inconsistent after much discussion the Panel considered that there was insufficient evidence to categorically refute any causal relationship between the subject motor accident and injury to the right shoulder, particularly involving labral tear. In particular, the Panel noted that there was no indication of any other causative factor with relation to any right shoulder injury. The Panel considered that it was plausible that the claimant sustained an injury to the right shoulder as a result of the subject motor accident and did not seek, or indeed perhaps require, any treatment until some time later when the persisting symptoms were brought to light when he was referred for specialist opinion. The Panel again discussed the inconsistencies and somewhat conflicting evidence and opinions presented by various examining specialists. The Panel accepted that in the face of insufficient evidence to the contrary, that the claimant did sustain an injury to the right shoulder as a result of the subject motor accident and that he had ongoing symptoms which eventually resulted in his having surgery carried out by Dr Bokor in October 2007. Furthermore, the Panel considered that the surveillance noted on DVD was not by and large inconsistent with a degree of continuing pathology involving the right shoulder." 21The Review Panel then reviewed medical reports which related to the condition of the first defendant's right shoulder after the operation. It set out its conclusion as follows: "Again evidence was conflicting but mainly with regards to the extent of any injury relating to the subject motor accident. There did appear to be consistent measured restriction in range of movement of the right shoulder following the subject motor accident and subsequent surgery." 22The Review Panel followed a similar process when dealing with the injury to the lumbar spine. It set out the first defendant's history of how the accident had occurred and a summary of his contemporaneous complaints at the West Wyalong Hospital and to the West Wyalong Medical Centre. As a result, the Review Panel said: "The Panel concluded that there was sufficient contemporaneous evidence of injury to the low back or lumbar spine as a result of the subject motor accident." 23The Review Panel then summarised the contents of medical reports concerning the first defendant's lumbar spine. As a result, the panel said: "The Panel concluded that although there was some pre-existing degenerative change and some reports of low back pain prior to the subject motor accident, this was not particularly significant and that there was sufficient contemporaneous evidence of injury to the claimant's low back as a result of the subject motor accident and that this included aggravation of pre-existing degenerative change. The Panel also concluded that there was no evidence of any other significant contributory causes, apart from long-term obesity, and in particular there was no evidence of any further or subsequent injury to the low back after the subject motor accident. The Panel therefore concluded that ongoing low back problems were related to the subject motor accident." 24After setting out the effect of further medical reports, the Panel said: "As indicated above, in consideration of all the evidence, the Panel concluded that there was sufficient evidence of an injury to the lumbar spine as a result of the subject motor accident and also felt that there was insufficient evidence to refute persisting symptoms with continuing aggravation and acceleration of degenerative change as a result of the subject accident. Again, the Panel noted the DVD surveillance. Although the claimant appeared to move quite freely and with no obvious pain, the Panel felt that the observed activities were not significantly inconsistent with a degree of ongoing pathology. The Panel also noted conflicting opinions regarding this in the reports on file but decided that there was sufficient doubt with regards to any inconsistency to conclude that the claimant did have significant ongoing problems with his low back. Again, the Panel accepted that the subsequent need for spinal fusion was as a result of persisting injury from the subject motor accident and again concluded that there was insufficient evidence to support the premise that such fusion was a result solely of natural progression of degeneration and that the subject motor accident had caused only a minor aggravation which had then resolved." 25The Review Panel concluded that the level of impairment of the right shoulder amounted to 11 percent and of the lumbar spine 20 percent so that in total the WPI exceeded 10 percent. Legal principle 26Both sides referred the Court to the decision of Wingfoot Australia Partners Pty Ltd v Kocak [2013] HCA 43 as the most recent statement of the obligations of a medical administrative decision maker to give adequate reasons. Senior counsel for the plaintiff relied upon its general statement as to the adequacy of reasons to be given but submitted that the scheme there under consideration was very different to the scheme of the MAC Act and that little further assistance could be obtained from the decision. Senior counsel for the first defendant, however, submitted that it was very much on point and that it provided guidance as to the matters, which a Medical Review Panel, such as that set up under the MAC Act, should consider when providing reasons. 27While the legislation applying to the Medical Panel in Wingfoot was different to the MAC Act, the function performed by the Medical Panel there and the MAS under the MAC Act is very similar. I accept that Wingfoot provides considerable assistance as to the function of a Medical Review Panel under legislation such as the MAC Act, and therefore the extent of its obligation to provide reasons for its decision. This is particularly so when pursuant to s 63(3A) of the MAC Act, the Review Panel has to make its own assessment. I consider the following parts of the judgment in Wingfoot to be relevant to the issues raised in these proceedings. "46 Two considerations are of particular significance in determining by implication the standard required of a written statement of reasons in order to fulfil the duty imposed on a Medical Panel by s 68(2) of the Act. One is the nature of the function performed by a Medical Panel in forming and giving an opinion on a medical question referred to it. The other is the objective, within the scheme of the Act, of requiring the Medical Panel to give a written statement of reasons for that opinion. 47 The function of a Medical Panel is to form and to give its own opinion on the medical question referred for its opinion. In performing that function, the Medical Panel is doubtless obliged to observe procedural fairness, so as to give an opportunity for parties to the underlying question or matter who will be affected by the opinion to supply the Medical Panel with material which may be relevant to the formation of the opinion and to make submissions to the Medical Panel on the basis of that material. The material supplied may include the opinions of other medical practitioners, and submissions to the Medical Panel may seek to persuade the Medical Panel to adopt reasoning or conclusions expressed in those opinions. The Medical Panel may choose in a particular case to place weight on a medical opinion supplied to it in forming and giving its own opinion. It goes too far, however, to conceive of the function of the Panel as being either to decide a dispute or to make up its mind by reference to competing contentions or competing medical opinions. The function of a Medical Panel is neither arbitral nor adjudicative: it is neither to choose between competing arguments, nor to opine on the correctness of other opinions on that medical question. The function is in every case to form and to give its own opinion on the medical question referred to it by applying its own medical experience and its own medical expertise. 48 The reasons that s 68(2) of the Act obliged the Medical Panel to set out in a statement of reasons to accompany the certificate as to its opinion were the reasons which led the Medical Panel to form the opinion that the Medical Panel was required to form for itself on the medical question referred for its opinion. What is to be set out in the statement of reasons is the actual path of reasoning by which the Medical Panel arrived at the opinion the Medical Panel actually formed for itself. ... 54 The objective, within the scheme of the Act, of requiring the Medical Panel to give a written statement of reasons for that opinion can therefore be seen to be that persons affected by the opinion automatically be provided with a written statement of reasons adequate to enable a court to see whether the opinion does or does not involve any error of law. There is an obvious benefit in requiring a written statement of reasons for an opinion always to meet that standard. The benefit is that it enables a person whose legal rights are affected by the opinion to obtain from the Supreme Court an order in the nature of certiorari removing the legal effect of the opinion if the Medical Panel in fact made an error of law in forming the opinion: an error of law in forming the opinion, if made, will appear on the face of the written statement. To require less would be to allow an error of law affecting legal rights to remain unchecked. To require more would be to place a practical burden of cost and time on decision-making by an expert body for no additional legal benefit and no identified systemic gain. 55 The standard required of a written statement of reasons given by a Medical Panel under s 68(2) of the Act can therefore be stated as follows. The statement of reasons must explain the actual path of reasoning by which the Medical Panel in fact arrived at the opinion the Medical Panel in fact formed on the medical question referred to it. The statement of reasons must explain that actual path of reasoning in sufficient detail to enable a court to see whether the opinion does or does not involve any error of law. If a statement of reasons meeting that standard discloses an error of law in the way the Medical Panel formed its opinion, the legal effect of the opinion can be removed by an order in the nature of certiorari for that error of law on the face of the record of the opinion. If a statement of reasons fails to meet that standard, that failure is itself an error of law on the face of the record of the opinion, on the basis of which an order in the nature of certiorari can be made removing the legal effect of the opinion. 56 The Court of Appeal considered that a higher standard was required of a written statement of reasons given by a Medical Panel under s 68(2) of the Act. On the premise that Brown held that the opinion of a Medical Panel must be adopted and applied for the purposes of determining all questions or matters arising under or for the purposes of the Act, the Court of Appeal analogised the function of a Medical Panel forming its opinion on a medical question to the function of a judge deciding the same medical question. Accordingly, it then equated the standard of reasons required of a Medical Panel with the standard of reasons that would be required of a judge giving reasons for a final judgment after a trial of an action in a court. The application of that judicial standard in circumstances where an affected party had provided to the Medical Panel opinions of other medical practitioners and had sought in submissions to rely on those opinions, and where the opinion formed by the Medical Panel itself did not accord with those opinions, meant that "it was incumbent on the [P] anel to provide a comprehensible explanation for rejecting those expert medical opinions or, if it be the case, for preferring one or more other expert medical opinions over them". Rejection of the premise and the analogy, for reasons already stated, entails rejection of the conclusion that the higher standard is required. A Medical Panel explaining in a statement of reasons the path of reasoning by which it arrived at the opinion it formed is under no obligation to explain why it did not reach an opinion it did not form, even if that different opinion is shown by material before it to have been formed by someone else. ... 58 The written statement of the Medical Panel's reasons for its opinion in the present case listed in a schedule the documents considered by the Panel. The listed documents included those described as "Plaintiff's Medical Reports" and "Defendant's Medical reports". The statement commenced with a recitation of agreed facts. The statement then set out the medical history taken by the Panel from the Worker, findings made by the Panel from its physical examination of the Worker, and findings made by the Panel from its viewing of the x-ray and MRI scan of the Worker's cervical spine. The statement then recorded the Panel's conclusion as to the nature of the Worker's current condition as reflected in the Panel's answer to Question 1: the Worker was suffering from chronic mechanical left cervical spine dysfunction with referred pain to his left shoulder girdle and upper limb. 59 Moving on to the process of reasoning adopted by the Medical Panel to answer Questions 2 and 3, the statement of the Panel's reasons recorded that the Panel considered the Worker's description of his employment duties, the history of his workplace injuries, medical reports of doctors who had treated and examined him, radiological results and its own examination. The statement then specifically recorded that the Panel noted various medical reports by one of the Worker's neurosurgeons and recorded that the Panel noted as well submissions on behalf of the Employer and the Worker, the thrust of which it summarised. The last six paragraphs of the statement were then as follows: ..." 28It is not necessary to set out those concluding six paragraphs of the Medical Panel opinion. What it did was to indicate its conclusion in that case. The effect of the conclusion was that the work incident caused soft tissue injuries, even though the Panel acknowledged that at the time of examination the worker was suffering from significant injuries to his neck but that these were not related to anything which occurred at work. 29The High Court went on to identify the complaint made by the worker and its resolution of that complaint: "62 As argument developed in this Court, it became apparent that the gist of the Worker's complaint about the adequacy of the statement of reasons is that the statement of reasons did not address the possibility that the degenerative changes resulting in the Worker's current condition were initiated on 16 October 1996 other than through soft tissue injury. His counsel submitted on his behalf "[i] t is a perfectly possible situation that a traumatic event can cause a soft tissue injury to ligaments and muscles and so forth and also cause an injury to the spine". That was, in the Worker's submission, the import of one of the medical reports, provided to the Medical Panel on behalf of the Worker, which was not addressed in the Panel's statement of reasons. The report, that of a neurosurgeon engaged by the Worker in 2009, expressed the opinion that what happened to the Worker on 16 October 1996 "would appear to be consistent with an injury to the cervical spine" and on that basis "may have resulted in intervertebral disc prolapse or an aggravation of underlying cervical spondylosis". 63 The answer to the Worker's complaint lies in the implicit finding of the Medical Panel that the Worker on 16 October 1996 sustained only a soft tissue injury, and not an injury to his spine. That finding was one of fact. Whether or not that finding of fact was open to the Medical Panel is a question of law. But no further explanation of the reasoning process adopted by the Medical Panel is necessary to enable a court to address that question." Submissions and consideration Causation - Amended Summons 5(a) and 5(e) 30The plaintiff submitted that the Review Panel had wrongly stated and applied the test of causation in relation to both the right shoulder and the low back. 31In relation to the right shoulder, the plaintiff criticised the following paragraphs of the Review Panel Certificate: "Although the contemporaneous evidence was somewhat inconsistent, after much discussion the panel considered that there was insufficient evidence to categorically refute any causal relationship between the subject motor accident and injury to the right shoulder, particularly involving labral tear. In particular, the Panel noted that there was no indication of any other causative factor with relation to any right shoulder injury. The Panel considered that it was plausible that the claimant sustained an injury to the right shoulder as a result of the subject motor accident and did not seek, or indeed perhaps require, any treatment until some time later when the persisting symptoms were brought to light when he was referred for specialist opinion. The Panel again discussed the inconsistencies and somewhat conflicting evidence and opinions presented by various examining specialists. The Panel accepted that in the face of insufficient evidence to the contrary, that the claimant did sustain an injury to the right shoulder as a result of the subject motor accident and that he had ongoing symptoms, which eventually resulted in having surgery, carried out by Dr Bokor in October 2007. Furthermore, the Panel considered that the surveillance noted on DVD was not by and large inconsistent with the degree of continuing pathology involving the right shoulder." 32In relation to the low back, the plaintiff focused on the following paragraphs of the Review Panel's Certificate: "The Panel concluded that there was sufficient contemporaneous evidence of injury to the low back or lumbar spine as a result of the subject motor accident. ... The Panel concluded that although there was some pre-existing degenerative change and some reports of low back pain prior to the subject motor accident, this was not particularly significant and that there was sufficient contemporaneous evidence of injury to the claimant's low back as a result of the subject motor accident and that this included aggravation of pre-existing degenerative change. The Panel also concluded that there was no evidence of any other significant contributory causes, apart from long-term obesity, and in particular there was no evidence of any further or subsequent injury to the low back after the subject motor accident. The Panel therefore concluded that ongoing low back problems were related to the subject motor accident. ... As indicated above, in consideration of all the evidence, the Panel concluded that there was sufficient evidence of an injury to the lumbar spine as a result of the subject motor accident and also felt that there was insufficient evidence to refute persisting symptoms with continuing aggravation and acceleration of degeneration change as a result of the subject motor accident. ... The Panel also noted conflicting opinions regarding this [i.e. the DVD surveillance] in the reports on file but decided that there was sufficient doubt with regards to any inconsistency to conclude that the claimant did have significant ongoing problems with his low back. Again, the Panel accepted that the subsequent need for spinal fusion was as a result of persisting injury from the subject motor accident and again concluded that there was insufficient evidence to support the premise that such fusion was a result solely of natural progression of degeneration and that the subject motor accident had caused only a minor aggravation which had then resolved." 33The plaintiff submitted that this approach was contrary to the MAA's Permanent Impairment Guidelines, published 1 October 2007, which relevantly provided: "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. The 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. 1.8 Causation is defined in the Glossary at p316 of the AMA 4 Guides as follows: "Causation means that a physical, chemical or biological 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 involved a medical decision and a non-medical informed judgment. 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." 34The plaintiff submitted that the approach of the Review Panel reversed the onus of proof in that it assumed that causation existed in relation to both medical conditions and then considered whether there was sufficient material to successfully refute such a causal relationship. 35The first defendant accepted that the Review Panel had expressed itself somewhat infelicitously on the issue of causation. He submitted that it was necessary to look at the totality of the reasoning behind the Review Panel's conclusions and to not focus upon isolated parts of its reasoning. In that regard, the first defendant relied upon the oft quoted statement of principle in Minister for Immigration and Ethnic Affairs v Liang [1996] HCA 6; 185 CLR 259 at 271 where the plurality said: "In other words, the delegate starts and finishes with the correct test; it is only some phraseology in between which provides the basis for a conclusion that she had slipped from an assessment of real chance to an assessment of balance of probabilities. When the Full Court referred to "beneficial construction", it sought to adopt an approach mandated by a long series of cases, the best exemplar of which is Collector of Customs v Pozzolanic. In that case, a Full Court of the Federal Court (Neaves, French and Cooper JJ) collected authorities for various propositions as to the practical restraints on judicial review. It was said that a court should not be "concerned with looseness in the language ... nor with unhappy phrasing" of the reasons of an administrative decision-maker. The Court continued: "The reasons for the decision under review are not to be construed minutely and finely with an eye keenly attuned to the perception of error". These propositions are well settled. They recognise the reality that the reasons of an administrative decision-maker are meant to inform and not to be scrutinised upon over-zealous judicial review by seeking to discern whether some inadequacy may be gleaned from the way in which the reasons are expressed." 36It is apparent from the way in which the Review Panel expressed itself in relation to the right shoulder, that it did reverse the onus of proof. It was only after it had analysed the matter in this way that it made any positive finding. That positive finding was undermined by the Review Panel's concluding observation which again reversed the onus of proof, i.e. the Panel accepted that in the face of insufficient evidence to the contrary, the claimant did sustain an injury to the right shoulder as a result of the subject motor accident. 37Regrettably, this error goes beyond a carelessness of expression, such as occurred in Liang, and indicates on the issue of the right shoulder injury a failure to apply the MAA's Permanent Impairment Guidelines and Common Law principles of causation. It constitutes an error of law on the face of the record. I have concluded that the plaintiff has made out its complaint in relation to causation with respect to the right shoulder injury. 38This is not so in relation to the low back injury. The Review Panel's initial finding (which was open to it) was that there was "sufficient contemporaneous evidence" supporting a causal connection between the injury to the low back and the motor accident. The Review Panel confirmed this positive finding when it had regard to the pre-existing degenerative changes but disregarded them. It was only after that positive finding had been made that the Review Panel considered whether there was evidence of any other significant contributing causes. 39That approach does not reverse the onus of proof and is an acceptable mode of reasoning towards a causation finding. It is consistent with the MAA Permanent Impairment Guidelines and the Common Law as to causation. Accordingly, the plaintiff has not made out its causation challenge to the Review Panel's finding in relation to the low back. Inadequacy of Reasons - Amended Summons 5(b), 5(c), 5(d) 40The plaintiff submitted that the Review Panel's reasons were inadequate in that it did no more than set out conclusions without revealing its reasoning process. The plaintiff submitted that such an approach was contrary to s61(9) of the MAC Act, which requires that a certificate set out the reasons for any finding by a medical assessor. The plaintiff submitted that there were competing medical opinions in the material before the Review Panel so that it was required when setting out its conclusions to indicate how these conflicts were resolved. 41The plaintiff, in aid of this submission, relied on the decision of Hall J in Allianz Australia Insurance Ltd v Francica [2012] NSWSC 1577; 63 MVR 1. The plaintiff submitted that Hall J had set aside the Medical Assessor's certificate in that case because it had not dealt with the disputed issues which had been referred to the Medical Assessor, and in that respect, the reasoning was inadequate. 42The first defendant submitted that in fact the Review Panel had sufficiently set out its reasoning process, so as to make clear the basis for its conclusions. In that regard, the first defendant relied upon the statements of principle in Wingfoot Australia. 43In accordance with the requirement in Wingfoot at [55], I am of the opinion that the Review Panel's Statement of Reasons explains the path of its reasoning in sufficient detail to enable a court to see whether the opinion did or did not involve an error of law. I agree with the first defendant that the function of the Review Panel was neither arbitral nor adjudicative and that it was not necessary for it to choose between competing arguments, nor to opine on the correctness of other opinions on a medical question. Its function was to form and give its own opinion as to the medical questions referred to it by applying its own medical experience and its own medical expertise (Wingfoot at [47]). This is what it did. In doing so, it sufficiently set out its reasoning process. 44In relation to the right shoulder injury, the Review Panel had regard to the DVD surveillance evidence and concluded that there was no clear evidence of the claimant elevating his right arm to a greater extent than that noted in a number of the reports relating to examination before surgery. That was a conclusion open to it and which was consistent with the opinions of Drs Bodel and Lahz. The Review Panel accepted that although the first defendant had not made immediate complaint concerning his right shoulder following the accident, it was "plausible" that he did not seek or require any treatment in relation to it until some time later when he sought specialist opinion. The Review Panel found that in the absence of any other evidence to explain the undoubted pathology in the first defendant's right shoulder, it was caused by the motor vehicle accident. 45Such an approach was open to the Review Panel based on the evidence before it. As the Review Panel made clear, it reached that conclusion after taking into account "conflicting evidence and opinions". What the Review Panel was not required to do was to refer to every contrary opinion and to explain why it was not prepared to accept that opinion. The observations in Wingfoot make that clear. 46The same conclusion follows from the Review Panel's approach to the injury to the low back. On that issue, the Review Panel noted immediate complaint following the accident. 47The Review Panel's reasoning process in relation to the low back injury is clear. Although there were some degenerative changes in the first defendant's low back before the accident, no investigations, treatment or specialist referrals took place in relation thereto. There was no evidence that his work was affected. In those circumstances the Review Panel concluded that the pre-existing degenerative changes played no part in his continuing low back problems except to the extent that they had been aggravated by the motor vehicle accident. 48Similarly, the immediate complaint and continuity of complaint concerning his low back following the motor vehicle accident enabled the Review Panel to conclude that the continuing symptoms and need for an operation were due to the motor vehicle accident. This was particularly so when no other cause, except his long term obesity, had been identified. In reaching that conclusion, the Review Panel had regard to the DVD surveillance material and concluded that the activities recorded were not significantly inconsistent with a degree of ongoing pathology. In reaching that conclusion it was not necessary for the Review Panel to examine every report to contrary effect and to explain why it did not accept that a contrary conclusion (Wingfoot at [47] and [56]). 49In the alternative, relying upon Minister for Immigration and Citizenship v Li [2013] HCA 18; 87 ALJR 618 the plaintiff submitted that the conclusion of the Review Panel was void for legal unreasonableness because of the overwhelming evidence to the effect that the claimant's long term obesity was a significant contributing factor to his continuing low back problems. The plaintiff submitted that it was unreasonable for the Review Panel not to give significant causal effect to the first defendant's obesity. 50This submission fails on a factual basis. While there was some evidence that his long-term obesity made a contribution to his continuing back problems, that evidence could not be properly characterised as "overwhelming". The best that could be said was that there was a body of opinion to that effect. 51Much of the medical opinion relating to the first defendant's low back condition made but passing reference to his obesity as a contributory factor. Of those that did, most followed the approach of Dr Yeo to the effect that "although there would have been progression of the L5/S1 disc problems because of other factors such as obesity and continuing to work, the subject motor accident caused aggravation and acceleration of degenerative change such that the requirement for spinal fusion had occurred a lot earlier than it would otherwise have done". 52In those circumstances it could not be said that the conclusion arrived at by the Review Panel was unreasonable or plainly unjust, i.e. that its conclusion lacked an "evident and intelligible justification" (Li at [76]). Failure to determine the "medical dispute" and take into account relevant considerations - Amended Summons 5(f), 5(g) and 5(h). 53The plaintiff submitted that the Review Panel failed to deal with and determine the "medical dispute" which had been referred to it as required by s 63 of the MAC Act. The plaintiff submitted that the Review Panel had failed to take into account relevant considerations, i.e. the plaintiff's written submissions. The plaintiff submitted that fundamental to a consideration of the medical dispute was a consideration of the first defendant's credit. It submitted that the Review Panel had failed to consider this issue. The plaintiff submitted that the finding by the Review Panel that "there did appear to be consistent measured restriction in range of movement of the right shoulder following the subject accident and subsequent surgery" was made without any evidence to support it and by reason thereof, the Review Panel's decision as to the right shoulder was invalid and should be set aside. 54The plaintiff submitted that by not having specific regard to its submissions, the Review Panel had in effect denied it procedural fairness. In that regard, the plaintiff relied upon on Kioa v West [1985] HCA 81; 159 CLR 550 and in particular the observations by Mason J at 584, 585 and 587. It also relied upon Re Minister for Immigration and Multicultural Affairs; Ex parte Lam [2003] HCA 6; 214 CLR 1 at [81] and Minister for Immigration and Citizenship v SZGUR [2011] HCA 1; 241 CLR 594 where French CJ and Kiefel J said: " Procedural fairness requires a decision-maker to identify for the person affected any critical issue not apparent from the nature of the decision or the terms of the statutory power. The decision-maker must also advise of any adverse conclusion which would not obviously be open on the known material. However, a decision-maker is not otherwise required to expose his or her thought processes or provisional views for comment before making the decision. ..." 55The first defendant submitted that it was clear from its certificate that the Review Panel had the plaintiff's written submissions before it and it stated that it had considered them. The first defendant submitted that there was no basis to support the plaintiff's assertion that this did not take place. In particular, the first defendant noted that the plaintiff had not identified any particular submission other than those relating to his credit which had not been taken into account. 56The first defendant submitted that the plaintiff's submission that there was no evidence concerning consistent restriction of movement of his right shoulder was misconceived. He submitted that this finding was an ultimate finding of fact based upon an extensive review of the medical evidence relating to the right shoulder. 57The plaintiff's submissions on these issues should not be accepted. 58It is not correct to say that the Review Panel failed to deal with and determine the "medical dispute". As the Review Panel correctly appreciated the issue before it on which the earlier opinions of the medical assessors differed, was that of causation. To resolve the causation issue required a review of the medical histories provided by the first defendant from time to time and also of the medical evidence based not only on those histories but on the findings of doctors who had examined him over the years. As is clear from its certificate, it was the issue of causation upon which the Review Panel focused. 59The real nub of the plaintiff's complaint is not that the "medical dispute" was not determined by the Review Panel but the proposition which has already been rejected that the Review Panel did not examine each medical opinion which was contrary to its conclusion on causation and explain why that opinion was incorrect. For the reasons already given, the Review Panel was not required to provide such reasons for its conclusion. It follows that this challenge has not been made out. 60The plaintiff's submission that the Review Panel did not have regard to its application and submissions and thereby denied it procedural fairness is to make the same submission in a different way. The basis of the plaintiff's complaint is that the Review Panel did not in terms deal with each of its submissions and indicate why it was not prepared to accept it. For the reasons already indicated, the Review Panel was not obliged to do so. 61In analysing and reviewing the medical evidence in the way in which it did, the Review Panel made clear not only what its conclusion was but why it had reached that conclusion. Those reasons implicitly identified the basis upon which the plaintiff's submissions were rejected. That was a sufficient discharge of the Review Panel's obligations under the MAC Act. 62It was not necessary or appropriate for the Review Panel to make a finding as to the credit of the first defendant. Apart from the fact that the Review Panel had not interviewed him, the reliability of the histories which he gave was part of the "inconsistencies" in the material before the Review Panel to which it referred and took into account when resolving the causation question. Accordingly, it was not necessary to make a finding in relation to any particular history given by the first defendant nor his history giving generally. 63There was ample evidence available to support the Review Panel's ultimate finding that there was consistent, measured restriction in range of movement of the right shoulder following the accident. As the first defendant submitted, this finding was an ultimate finding of fact based upon an extensive review of the evidence relating to the right shoulder which was set out in the preceding four pages of the certificate. Amongst other things, the Review Panel identified that the surveillance evidence was consistent with the limitations on range of movement described by the first defendant. 64It follows that these challenges to the Review Panel's certificate have not been made out. Conclusion 65The plaintiff has succeeded in establishing its first proposition, i.e. that the Review Panel wrongly stated and applied the test of causation to its assessment of the degree of permanent impairment of the first defendant's right shoulder as a result of the injury caused to it by the motor accident. Given the role of a medical assessment certificate under the MAC Act, I do not consider that it is appropriate to sever that part of the Review Panel's certificate relating to the right shoulder from the balance of the certificate. In other words, this error on the part of the Review Panel being an error of law on the face of the record invalidates the whole of the certificate. 66Accordingly, the orders which I make are as follows: (1) I make an order in the nature of certiorari quashing the Review Panel's certificate, issued on 22 July 2013. (2) I order that the matter be reallocated to a Medical Assessor Review Panel for determination according to law. Costs 67No submissions were made by the parties as to costs. Accordingly, I reserve the question of costs so as to allow the parties the opportunity of making submissions having regard to these reasons.