Kitching v AAI Ltd t/as GIO Insurance

The proceedings

1. By a summons filed 9 July 2019 the plaintiff sought an order in the nature of certiorari setting aside the decision of the Proper Officer, and seeking an order that the State Insurance Regulatory Authority (the second defendant) refer the medical assessment certificate of Dr Home of 4 January 2019 to the Review Panel.
2. By an amended summons filed 9 October 2019, the plaintiff sought an order in the nature of certiorari setting aside the certificate of Dr Home dated 4 January 2019 and/or the decision of the Proper Officer made on 11 April 2019 dismissing the plaintiff's application for review of the medical assessment certificate. She also sought an order that the Authority arrange a medical assessment pursuant to s 61 of the Motor Accidents Compensation Act 1999 (NSW), for the purpose of assessing the plaintiff's whole person impairment, or referring the medical assessment certificate of Dr Home of 4 January 2019 to the Review Panel.
3. A further amended summons filed 30 June 2020 made only cosmetic changes, naming Dr Home and the Proper Officer, Tajan Baba, as the third and fourth defendants respectively.
4. The relief sought in respect of Dr Home was not brought within the three month period specified in rule Part 59.10 of the Uniform Civil Procedure Rules 2005 (NSW). The plaintiff sought an extension of time under subr 10(2). The extension was not opposed. Having considered the matters in subr (3), I consider that time should be extended to the date of filing the Amended Summons.
5. The plaintiff's summons contained 25 separate grounds said to justify judicial review, with the grounds alleging that both the third and the fourth defendants erred at law and/or committed jurisdictional error by doing a number or things or failing to do a number of things. There were 11 such grounds in respect of the third defendant, and 14 such grounds in respect of the fourth defendant.
6. In relation to the Assessor, Dr Home, as the plaintiff's written submissions made clear, the complaints can be distilled to three matters. The first was said to be an error of law on the face of the record in relation to a finding by the Assessor that no additional pathology was found on post-accident imaging of the lumbar spine. The error was said to be that the conclusion that no additional pathology was found was not supported by the reasoning process in the report. It was said further that there were no reasons to explain why the Assessor preferred Dr Cummine's view to that of Dr Dixon. Dr Cummine, who was retained by the defendant, had found that the surgery the plaintiff underwent in 2017 was not causally related to either accident. He found only soft tissue injury from the second accident, and said he was not able to identify any permanent whole person impairment of her lumbar spine.
7. Secondly, it was said that the Assessor did not engage with the plaintiff's clearly articulated case, as identified in Dr Dixon's report, that there was a progression in the pathology subsequent to the second accident which led to the spinal fusion surgery that the plaintiff underwent in 2017.
8. Thirdly, it was said that the Assessor did not consider clauses 1.7 to 1.9 of the Permanent Impairment Guidelines, did not address their content, and did not deal with causation by the medical and non-medical determinations that the Guidelines required.
9. Both sides accepted that the relief sought in relation to the fourth defendant would stand or fall on the outcome of the relief sought against the third defendant.

The radiology

1. So that the competing arguments can be understood, it is necessary to set out some of the background radiology, accepting, of course, that the court's task does not involve a merits review of the plaintiff's complaints, and the acceptance or rejection of them. The plaintiff's injuries involved her cervical spine as well as the lumbar spine, and some scans involved both those parts of her back. It should also be noted that the plaintiff had pre-existing lower back problems, as the radiology discloses. The following summary is taken from the report of the Assessor.
2. CT scans of the lumbar spine dated 13 June 2012 relevantly noted, At L4/5, there is minor prominence at the posterior disc annulus slightly more marked on the left. No significant foraminal stenosis is seen. No nerve root impingement is identified. At L5, there are bilateral pars interarticularis defects with grade 1 anterolisthesis of L5/S1 of 4mm. There is mild associated L5/S1 central disc protrusion. There is mild foraminal narrowing bilaterally, however, no definite L5 nerve root impingement is seen. No impingement of descending S1 nerve root is identified.
3. CT scans of the lumbar spine dated 9 January 2014 demonstrated, minor spondylolisthesis at L5/S1 associated with chronic pars defects. The spondylolisthesis measures less than 3mm. At L4/5, there is slight reduction in disc height. At L4/5,there is subtle left paracentral broad based disc bulge slightly indenting the thecal sac lying close to the left L5 nerve root origin. No focal disc abnormality at L5/S1.
4. An MRI of the whole spine on 2 June 2014 disclosed, in relation to the lumbosacral spine: Bilateral L5 pars defects. There is disc dehydration at L4/5 and L5/S1. At L4/5, a posterior central annulus tear on a background of diffuse disc bulge. No disc protrusion or neural compression is seen. There is no spinal canal or foraminal stenosis. At L5/S1, there is a subtle posterior central annulus tear on a background of a minimal disc bulge. No disc protrusion or neural compression is seen. There is no spinal canal or foraminal stenosis. There is grade 1 anterolisthesis of L5 on S1 of 3mm due to bilateral L5 pars defects.
5. There was one MRI taken after the first accident, but before the second accident, on 26 May 2015. It showed this: In the lumbosacral spine, there is disc desiccation at L4/5 and L5/S1 with preservation of intervertebral disc space height and minor broad based disc bulging at L4/5. Pars defects bilaterally at L5.
6. After the second accident an x-ray was performed on 1 December 2016, which was followed by an MRI of the lumbar spine. The x-ray findings were these: There is spondylolistheses at L5/S1 level. There is spondylolysis. Vertebral body heights are normal.
7. The Assessor said of the MRI of the lumbar spine on 1 December 2016 that it, demonstrated a pars defect at L5 with mild anterolisthesis at L5/S1, annulus fissure at L5/S1.

Dr Dixon

1. Dr Dixon was the plaintiff's independent medico-legal assessor. His report of 7 June 2018 first listed the documents that he had received. These included the MRIs of 26 May 2015 and 1 December 2016. Dr Dixon noted the accident details that were provided by the plaintiff. He noted that she had transient low back pain from the first accident. In relation to the second accident he said: Her main injury in the second accident was her back strain injury and after radiological investigation, she subsequently had operative intervention with posterolateral fusion with segmental fixation with pedicle screws at L5/S1. … She has a past history of low back pain during one of her pregnancies which settled with conservative management.
2. In the section of his report headed "General health, including subsequent or previous accidents", nothing was said about any prior back problems.
3. Dr Dixon summarised a large number of radiological investigations undergone by the plaintiff, including the MRIs of 26 May 2015 and 1 December 2016, and the x-ray of the lumbar spine on 1 December 2016. In relation to these he said, MRI of the cervical and lumbar spine on 26 May 2015… In the lumbar spine there was a mild disc bulge at L4/5 with bilateral pars defects without gross spondylolisthesis. MRI of the lumbar spine on 1 December 2016 showed pars defects at L5 with mild anterolisthesis at L5/S1 and an annular tear at L4/5 with a posterior disc bulge.
4. He also noted the following investigations: CT of the lumbar spine on 9 January 2014 showed bilateral pars defects at L5/S1 with minimal L5/S1 spondylolisthesis and a subtle left paracentral disc bulge at L4/5. Whole spine MRI on 12 June 2014 showed … [i]n the lumbar spine there was an annular tear at L4/5 with a diffuse disc bulge and at L5/S1 a subtle annular tear with a minimal disc bulge at L5/S1 with a grade 1 anterolisthesis of L5 on S1 due to bilateral pars defects.
5. In the section of his report headed "Summary of injuries and diagnoses", the following appears: In summary this claimant sustained neck and shoulder strain injuries in the first motor vehicle accident on 12 May 2015 with transient low back strain injury and in the second motor vehicle accident, she had a severe low back strain injury with post traumatic stiffness with aggravation of pre-existing asymptomatic spondylolysis which is ongoing. She subsequently required a lumbosacral posterior lateral spinal fusion. Her diagnoses for the first motor vehicle accident on 12 May 2015 are: … 4. Transient aggravation of her lower back; … Causation The above injuries are casually related to the injuries received in the subject motor vehicle accident on 12 May 2015. The diagnoses for the accident on 12 June 2016 are as follows: 1. Low back strain injury with post traumatic lumbar stiffness with L5/S1 posterolateral fusion with segmental fixation with aggravation of previously asymptomatic lumbosacral spondylolisthesis; 2. Radicular complaint with right L5 radiculopathy; … Causation The above conditions are casually related to the injuries received in the subject motor vehicle accident on 15 June 2016.

Dr Cummine

1. Dr Cummine prepared two reports. The first was dated 30 May 2016 in respect of an examination on 26 May 2016. Its only present relevance is that Dr Cummine had available to him radiology which included scans of the lumbosacral spine on 9 January 2014, 2 June 2014 and 26 May 2015. In relation to the MRI of 26 May 2015 Dr Cummine noted the following:

• Bilateral L5 pars defects, without significant reactive change or associated listhesis.
• The conus terminates at L1.
• Minor broad based disc bulging at L4/5.
• No canal stenosis, lateral recess stenosis or foraminal stenosis.

1. His second report, which post-dated the second accident, was dated 27 November 2018. In that report Dr Cummine referred to further imaging, being the CT of the lumbosacral spine on 17 November 2016 which he said showed no significant change from the earlier CT scan, and the plain x-ray of the lumbosacral spine performed on 1 December 2016. Dr Cummine said that that x-ray showed no significant change. Spondylolysis at L5/S1 is noted along with the pars defect at L5 bilaterally. Dr Cummine does not mention seeing the MRI carried out on 1 December 2016.
2. In the section of his report headed "Summary", Dr Cummine said this: Following the initial accident on 12.5.2015, I consider this woman has had sustained minor soft tissue injuries to the neck and low back. I noted a past history of multiple previous injuries to her neck, a previous history of injury to her low back, resulting in back pain, and the identification of bilateral Pars defects with an equivocal minimal spondylolysis at L5/S1. In situ degenerate disc disease was present prior to that accident. Since my last review, she was involved in a second accident on 15.6.2016, with aggravation of both neck and back symptoms. ... I consider in the second accident on 15.6.2016 she may have sustained minor soft tissue injuries again temporarily aggravating some pre-existing symptoms in both her neck and back. I do not think the second accident materially altered her clinical course.
3. In answer to a specific question asked of him, Dr Cummine said that he did not think the surgery at L5/S1 was causally related to either accident.

Assessor's report

1. The report from the Assessor and his Certificate is dated 4 January 2019 in respect of an assessment on 20 December 2019.
2. The Assessor first detailed the plaintiff's pre-accident medical history and relevant personal details. He next set out the history of each of the motor accidents.
3. When dealing with the history of the plaintiff's symptoms and treatment following the accidents, the Assessor said: Ms Kitching recalls early pain in her right hip and groin and further pain in the right side of her lower back. … She recalls that during late 2016 and early 2017, her back pain symptoms increased. She recalls development of further symptoms in her right leg. She attended Dr Gray in March 2017. He subsequently recommended spinal fusion surgery. This was performed on 6 June 2017 as a posterior interbody lumbar fusion with screw fixation. She recalls that the surgery was relatively successful in improving the severity of her back pain that had been very severe since early 2017.
4. Under the heading "Current symptoms", the Assessor said: There is pain in the lower back of average intensity 3/10, exacerbated by prolonged sitting. There is exacerbation of buttock pain with coughing and sneezing. She described radiation of pain to the back of the thighs as far as the knee. She experiences local pain in both insteps with prolonged sitting.
5. The Assessor then recorded his findings on clinical examination.
6. In the section headed "Review of documentation" the Assessor summarised the various radiological reports commencing with the CT of the lumbar spine of 13 June 2012 and going through, relevantly, to the x-ray and MRI undertaken on 1 December 2016. In relation to the MRI performed on 26 May 2015, the Assessor relevantly said: In the lumbosacral spine, there is disc desiccation at L4/5 and L5/S1 with preservation of intervertebral disc space height and minor broad based disc bulging at L4/5. Pars defects bilaterally at L5.
7. In relation to the MRI performed on 1 December 2016, the Assessor said: MRI lumbar spine on 1 December 2016 demonstrated a pars defect at L5 with mild anterolisthesis at L5/S1, annulus fissure at L5/S1.
8. The Assessor then surveyed the various medical reports in respect of the plaintiff dating back to 2010. The survey was detailed, and extended over more than six pages of his report. When dealing with Dr Dixon's report, the Assessor said this: The report of Dr Dixon dated 27 June 2018 documents the medical history in relation to the motor vehicle accidents of 12 May 2016 and 16 June 2016. The past history set out on page 3 of the report is incomplete and does not enclose the prior history of chronic neck pain and associated headache or the history of recurrent lower back pain with radiculopathy as enclosed in the medical file. … In relation to the second motor vehicle accident, Dr Dixon found clinical signs of a right L5 radiculopathy, however, those clinical signs are not reproduced at the current assessment.
9. In relation to the reports of Dr Cummine, the Assessor noted that Dr Cummine's first report preceded the second motor vehicle accident. The Assessor dealt mainly with what Dr Cummine said about the cervical and left shoulder area. As far as the lumbar spine was concerned, the Assessor noted that Dr Cummine made a diagnosis of minor soft tissue injury to "possibly the thoracic and/or lumbar spine." He said that Dr Cummine found the nature of the history of a pre-existing condition in the lumbar region was not affected by the first accident.
10. In relation to the second report of Dr Cummine, the Assessor said this: I reviewed the further report of Dr Cummine, who documents the second motor vehicle accident on 15 June 2016 with subsequent complaint of neck pain treated in a Miami J collar and further imaging with MRI scanning with referral to Dr Randolph Gray. He documents the onset of symptoms in the right leg causing her to fall to the ground and does document the subsequent fusion surgery as an anterior lumbar interbody fusion with posterior pedicle screws and grafting with subsequent improvement in symptoms. Surgery had helped her back pain. At examination. Dr Cummine found that neck motion was approximately half normal range. There was a healed midline surgical scar in the lumbar spine. He found that rotation was full. Forward flexion was reduced. Extension was to two thirds normal range. She had a three quarters squatting capacity. He documented marked restriction of active motion at both shoulders which were symmetrical with full internal and external rotation. There was voluntary jerking of the body and limbs when testing reflexes. Straight leg raise was symmetrical but he does not document other neurological findings apart from the lack of wasting. Dr Cummine opined that in the second accident of 15 June 2016, there had been aggravation of both neck and back pain symptoms. Subsequently, in 2017, she underwent an anterior lumbar interbody fusion with posterior screw fixation with self reporting of some improvement in symptoms but significant ongoing symptoms in the lower back and neck. He considered there to be a significant contribution to the clinical picture from a chronic pain syndrome. He found in the second accident she may have sustained minor soft tissue injuries again temporarily aggravating some pre-existing symptoms in both her neck and back but he did not consider the second accident materially altered the clinical course. Consequently, he opined there was no permanent medical impairment arising from either motor vehicle accident.
11. In his conclusions, the Assessor said that it was not apparent that there had been any material aggravation of a pre-existing, episodic lower back pain in the first motor vehicle accident. In relation to the second accident the Assessor said this: I am satisfied from the second motor vehicle accident the claimant sustained early complaints of right sided lower back pain. The claimant sustained a soft tissue injury to the lumbar spine. Post accident imaging demonstrates the same pathology as was evident prior to the first motor vehicle accident, that is, a longstanding L5/S1 grade 1 spondylolisthesis due to bilateral developmental pars defects at L5. No additional pathology was found on post-accident imaging of the lumbar spine. It appears that the claimant developed more prominent symptoms of lower back pain with radicular features extending to the right leg, for which she attended Dr Gray around March 2017, leading on to the recommendation for a posterior interbody lumbar fusion procedure. It appears that the surgery has been successful in reducing her level of back pain and her lower limb symptoms. The requirement for fusion surgery arises from the underlying developmental spondylolisthesis, which was pre-existing. There is insufficient evidence to determine that the motor vehicle accident has materially aggravated the underlying pathology or that it led to the requirement for subsequent fusion surgery. I have carefully reviewed the clinical notes prepared by Dr Zerounian and Dr Mellows between the date of the subject second motor accident of 15 June 2016 and the date of surgery, it is noted that at first review, the main focus of tension was her cervical spine. There was no evidence of significant aggravation of the lower back condition. On 5 July 2016, Dr Mellows documents complaints of severe pain from the occiput around the head to the front, exacerbated by walking, with clinical findings confined to the examination of the cervical spine. On 9 August 2016, Dr Mellows documented complaints of vertigo with exercise. There was documentation of reduced flexion of the lumbar spine due to stiffness but found lateral flexion and extension were full. The diagnosis was flare up of chronic pain due to the previous motor vehicle accident. On 23 August 2016, there was documentation of urinary frequency related to sitting, but again this is considered to be a consequence of her neck injury. It is not until 4 November 2016 that there was then record of ongoing right sided lower back pain and hip pain since the motor vehicle accident in June with pain radiating to the hamstring region. Even at that stage, the main focus of complaint was the right hip, where there was pain elicited with rotation. Straight leg raise was normal, with minimal hamstring pain. There was some doubt about the diagnosis. It is noted that CT scans of the lumbar spine were requested in November 2016. There is clear documentation that the pain became worse around late 2016 and this is also documented by Dr Gray at first assessment on 24 March 2017 when he documents that symptoms became progressively worse over the last few months. The same history is recorded in his subsequent report of 10 May 2017. I note further the opinion of Dr Cummine and I agree with the opinion of Dr Cummine that it does not appear that the motor vehicle accident itself has caused an alteration in the trajectory of her pre-existing condition. (emphasis added)

Submissions

1. Although the grounds of appeal concerned with the Assessor's decision were widely expressed, as I have noted earlier senior counsel for the plaintiff put the basis for judicial review in three ways. First, the finding of the Assessor that "no additional pathology was found on post-accident imaging of the lumbar spine" was said to be an error. It was described by the plaintiff's senior counsel as a reasons error because no reasons were given for that conclusion. The plaintiff submitted that there were no reasons why Dr Dixon's opinion on the MRI imaging and the causal pathways consequent upon it was to be rejected. The error was said to have come about partly, at least, because the Assessor did not appreciate that Dr Cummine, with whom the Assessor agreed, did not view the MRI of 1 December 2016.
2. Secondly, the plaintiff submitted that the Assessor did not engage with the plaintiff's clearly articulated case based on what was shown in the changes on the MRIs from May 2015 to December 2016. That clearly articulated case was said to be demonstrated in Dr Dixon's report. The case was that the scans showed a material change in the plaintiff's lumbar spine, which demonstrated that the surgery undergone by the plaintiff was causally related to the second accident.
3. Thirdly, the plaintiff submitted that the Assessor did not apply the causation guidelines and he did not address their content. The plaintiff submitted that the Assessor did not deal with causation by the steps contained in those guidelines by making the medical and the non-medical determinations. The plaintiff submitted that the case had always been that there was a pre-existing condition which was aggravated, accelerated or exacerbated by the second motor vehicle accident. The plaintiff submitted that the Assessor did not address material contribution in a recognisable manner, and that the negative causation finding speaks to an incorrect - but not articulated - test having been applied.
4. As far as the complaint against the Proper Officer is concerned, the plaintiff accepted that her success on that matter stood or fell with the outcome of her complaint against the Assessor.
5. The defendant submitted that what a large number of the grounds of appeal invited was a merits review of complex imaging and of the Assessor's opinion. The defendant submitted that authorities such Rodger v De Gelder [2015] NSWSC 1617 demonstrate that what must be shown is error within the statutory function and not just an allegedly erroneous conclusion.
6. The defendant submitted that there was no obligation on the Assessor to examine the opinions of Dr Dixon to see whether those opinions were correct. The Assessor's function was to form his own opinion on the medical question applying his own medical expertise. The defendant submitted that the Assessor carried out that exercise.
7. The defendant submitted that there was no clearly articulated case which the Assessor failed to deal with. The defendant submitted that Dr Dixon did not articulate a case that demonstrated a change in the pathology. The defendant submitted that the premise of the argument was wrong because the radiological evidence demonstrated similar pathology prior to the first accident, as the Assessor had noted.

Error and inadequate reasons

1. In Layt v Allianz Australia Insurance Ltd [2016] NSWSC 1107 Garling J said: [65] …[I]t is necessary for this Court to keep in mind that one does not approach the reasons of the Review Panel as though they are the equivalent of a judgment, or a form of judicial reasons resolving a dispute in an adversarial context. Section 63(3A) of the MAC Act obliges the Review Panel to undertake "… a new assessment of all the matters with which the medical assessment is concerned". The Court of Appeal identified the function being exercised by the Review Panel under the MAC Act in Frost v Kourouche [2014] NSWCA 39; (2014) 86 NSWLR 214 as being sufficiently analogous to the Victorian motor accident scheme described by the High Court of Australia in Wingfoot Australia Partners Pty Ltd v Kocak [2013] HCA 43; (2013) 252 CLR 480. [66] In Wingfoot, the High Court was dealing with an issue relating to the adequacy of reasons given by a Medical Panel. The statutory obligations are sufficiently similar. In NSW, s 61(9) of the MAC Act provides that the Certificate is to "… set out the reasons for any finding by the medical assessor … as to any matter certified in the certificate". In Victoria, the legislation obliged the Panel to provide "… a written statement of reasons for [its] opinion". At [47] in Wingfoot, the High Court said: "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."
2. In Dunbar v Allianz Australia Insurance Limited [2015] NSWSC 119, Fullerton J said at [78]: Counsel's approach not only proceeded on the wrong assumption that Dr Cameron was obliged to set out in detail his review of the full complement of the reports and other material relied upon by the plaintiff in the assessment process in the reasons for decision, and to account for the consideration he gave to that material, but it involved a reading of the reasons in segmented parts for their legal sufficiency contrary to the principles of judicial review which require the reasons to be read as a whole. An administrative decision maker in the position of Dr Cameron as a medical assessor under the Act is not required to specify in the reasons for decision which accompany the issue by him of a certificate under s 61(1) why he did or did not accept certain matters, or why he did not consider a matter to be relevant to the evaluation of impairment - although, of course, he may have chosen to do so. His only duty is to supply reasons for the decision after undertaking the assessment in accordance with the Act and in compliance with the Guidelines (see Minister for Immigration and Multicultural Affairs v Yusuf [2001] HCA 30; 206 CLR 323 and Re Minister for Immigration and Multicultural and Indigenous Affairs; ex parte Palme [2003] HCA 56; 216 CLR 212).
3. In Bradley v Insurance Australia Ltd t/as NRMA Insurance [2015] NSWSC 950, Adamson J said: [44] The Review Panel is a "medical" Review Panel and its members are medical specialists who are required to undertake a "medical assessment". Its obligation to give reasons required it to set out "the actual path of reasoning" by which it arrived at the assessment: Wingfoot Australia Partners Pty Limited v Kocak [2013] HCA 43 at [48] (Kocak); Frost v Kourouche [2014] NSWCA 39. The reasons actually stated are to be understood as recording the steps that were in fact taken at arriving at that result: Waterways Authority v Fitzgibbon [2005] HCA 57 at [130] per Hayne J. [45] Some latitude is to be given to the reasons of an administrative decision-maker, which are not to be construed "minutely and finely with an eye keenly attuned to the perception of error" (Collector of Customs v Pozzolanic [1993] FCA 322; 43 FCR 280) and are to be given what has been referred to as a "beneficial construction": Minister for Immigration and Ethnic Affairs v Wu Shan Liang [1996] HCA 6; 185 CLR 259 at 271-272. However, a beneficial construction does not permit reasons to be inferred which are not stated if they are not necessarily implied by what is expressed: SZCBT v Minister for Immigration and Multicultural Affairs [2007] FCA 9 at [26] per Stone J. Although reasons need not be extensive, where more than one conclusion is open it is necessary for the decision-maker to explain a preference for one conclusion rather than another: Campbelltown City Council v Vegan [2006] NSWCA 284; 67 NSWLR 372 at [121]-[122] per Basten JA. [46] The function of the Review Panel is fundamental to the way in which its reasons are to be read. In Kocak, the High Court considered a scheme analogous to the one that applies in the present case. At [47] the High Court (French, CJ. Crennan, Bell, Gageler and Keane JJ) said (omitting footnotes): The function of a Medical Panel is to form and to give its own opinion on the medical question referred for its 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. [47] That the Review Panel's function is "neither arbitral nor adjudicative" has significant consequences for both the first and the second grounds. As far as the first ground is concerned, it means that the panel's decision about causation is not to be arrived at by the processes that would be used in a court room. [48] Although the Review Panel was obliged to be "aware" of the common law principles that would be applied in a court (cl 1.7, Permanent Impairment Guidelines), it was not necessary for the Review Panel to address s 5D of the Civil Liability Act, much less the decisions of this Court or higher courts on the question of causation. I do not, in any event, discern any inconsistency between the way in which the Review Panel approached the question of causation (which is pre-eminently a factual one, see Hunt & Hunt Lawyers v Mitchell Morgan Nominees Pty Ltd [2-13] HCA 10; 247 CLR 613, at [43] per French CJ, Hayne and Kiefel JJ) and the principles that apply in a court.
4. In Allianz Australia Insurance Ltd v Cervantes [2012] NSWCA 244, Basten JA (McColl and Macfarlan JJA agreeing) said, at [16], that how a consideration is to be taken into account and what weight is to be accorded to it in all the circumstances are matters within the authority of the decision-maker.
5. The conclusions that the Assessor made and which are challenged by the plaintiff are: No additional pathology was found on post-accident imaging of the lumbar spine. and It does not appear that the motor vehicle accident itself has caused an alteration in the trajectory of her pre-existing condition.
6. In reaching those conclusions the Assessor had regard to all of the prior doctors' reports, all of the radiology, and his own assessment of the plaintiff. The Assessor explained how he reached his conclusion that it did not appear that the motor vehicle accident itself had caused an alteration in the trajectory of her pre-existing condition. The Assessor had noted that post-accident imaging demonstrated the same pathology as was evident prior to the first motor vehicle accident. He said that there was insufficient evidence to determine that the second motor vehicle accident had materially aggravated the underlying pathology or that it led to the requirement for subsequent fusion surgery. The Assessor particularly noted clinical and other medical notes in the period from the second accident up until the emergence of right-sided lower back and hip pain in November 2016.
7. The plaintiff is critical of the Assessor because she said that the Assessor does not appear to take into account that Dr Cummine did not have regard to the MRI of 1 December 2016. The important matter is, however, that the Assessor did have regard to that MRI, and reached his own conclusion taking that MRI into account. It is also apparent from the Assessor's remarks that he had reached his conclusion that the second motor vehicle accident was not causally related to the need for surgery before he expressed his agreement with the opinion of Dr Cummine. In that way, nothing flows from the fact that Dr Cummine did not have access to that MRI.
8. The Assessor does not indicate that he is preferring the opinion of Dr Cummine to that of Dr Dixon. It is clear, however, that he took into account Dr Dixon's views but those views did not accord with his own. The Assessor noted that Dr Dixon's past history was incomplete and did not refer to the history of recurrent lower back with radiculopathy as was disclosed in the plaintiff's medical file. He noted also that although Dr Dixon found clinical signs of a right L5 radiculopathy, the Assessor did not find those clinical signs reduced on his assessment. In that way, the Assessor explained why he reached the view that the second motor vehicle accident did not change the trajectory of the plaintiff's pre-existing condition. Such an approach entirely satisfies what the authorities cited above require and, in relation to more than one conclusion being open, accords with what was said by the Court of Appeal in Campbelltown City Council v Vegan (2006) 67 NSWLR 372; [2006] NSWCA 284 at [121].
9. The plaintiff's argument was that the MRI taken on 1 December 2016 shows a change in the pathology of the lumbosacral spine. The plaintiff submitted that the Assessor erroneously said that that imaging did not show a change in her condition. In the first place, it needs to be observed that such an assertion is effectively seeking a merits review of the Assessor's conclusions. I accept the defendant's submission that for error to be shown, it is not sufficient to challenge a conclusion reached by the Assessor, but to show that there was some failure to comply with the Assessor's statutory function or to show some error of process.
10. The Assessor's task was to give [his] own opinion on the medical questions referred to [him] by applying [his] own medical experience and [his] own medical expertise: Wingfoot at [47].
11. The plaintiff fails to demonstrate that the Assessor erred in his conclusions, or that his reasons are inadequate by failing to outline the path that led him to his conclusions, or that there was any failure in the decision-making process.

Plaintiff's clearly articulated case

1. What was said in Dranichnikov v Minister for Immigration and Multicultural Affairs [2003] HCA 26; 77 ALJR 1088, at [24], was: To fail to respond to a substantial, clearly articulated argument relying upon established facts was at least to fail to accord Mr Dranichnikov natural justice.
2. The plaintiff's written submissions put the "clearly articulated case" widely. It was said that the second accident aggravated, accelerated or exacerbated the plaintiff's pre-existing condition. In oral submissions, the argument was refined to say that the case as appeared in Dr Dixon's report was a change in the pathology as shown in the 1 December 2016 MRI. The plaintiff submitted that the Assessor did not engage with that argument.
3. It is certainly not apparent from Dr Dixon's report that he was suggesting that there had been a change in pathology demonstrated by the MRI of 1 December 2016. His diagnosis for the second motor vehicle accident was relevantly said to be: 1. Low back strain injury with post-traumatic lumbar stiffness with L5/S1 posterolateral fusion with segmental fixation with aggravation of previously asymptomatic lumbosacral spondylolisthesis; 2. Radicular complaint with right L5 radiculopathy.
4. However, even if it can be inferred that the plaintiff's case was, by virtue of Dr Dixon's report, that there had been a change in the pathology or, even absent a change in pathology, that there had been an aggravation, acceleration or exacerbation of the pre-existing condition, the Assessor directly engaged with that aspect of the matter. The Assessor set out a summary of all the radiology from 2012 through to 2017. In that regard, it may be observed that the MRI of 2 June 2014 is reported on in almost the same way as the MRI of 1 December 2016. The Assessor then engaged directly with the matter of any change of pathology when he said: Post-accident imaging demonstrates the same pathology as was evident prior to the first motor vehicle accident, that is, a longstanding L5/S1 grade one spondylolisthesis due to bilateral development pars defects at L5. No additional pathology was found on post-accident imaging of the lumbar spine.
5. On the wider issue of aggravation, acceleration or exacerbation, the Assessor said: It appears that the claimant developed more prominent symptoms of lower back pain with radicular features extending to the right leg, for which she attended Dr Gray around March 2017, leading on to the recommendation for a posterior interbody lumbar fusion procedure. It appears that the surgery has been successful in reducing her level of back pain and her lower limb symptoms. The requirement for fusion surgery arises from the underlying developmental spondylolisthesis, which was pre-existing. There is insufficient evidence to determine that the motor vehicle accident has materially aggravated the underlying pathology or that it led to the requirement for subsequent fusion surgery.
6. While those two related conclusions differ from what the plaintiff asserts is the position, it is far from clear that the lack of any additional pathology on the imaging differs from what Dr Dixon records in his report. In any event, both conclusions were open to the Assessor, in terms of his function of forming and giving his own opinion on the medical question referred to: Wingfoot at [47].
7. Significantly, the Assessor did not fail to engage with the issue. He simply came to a different conclusion from that which the plaintiff submitted was the case.

Permanent Impairment Guidelines

1. Clauses 1.6 to 1.9 of the Permanent Impairment Guidelines relevantly provide: 1.6 Causation is defined in the Glossary at page 316 of the AMA4 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: 1. The alleged factor could have caused or contributed to worsening of the impairment, which is a medical determination. 2. 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. 1.7 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. Impairment and disability 1.8 it is critically important to clearly define the term impairment and distinguish it from the disability that may result. 1.9 Impairment is defined as an alteration to a person's health status. It is a deviation from normality in a body part or organ system and its functioning. Hence, impairment is a medical issue and is assessed by medical means.
2. The plaintiff submitted that no particular attention was paid to the medical question and non-medical question when assessing causation.
3. Whilst it is not necessary for the Assessor to make specific reference to the Guidelines, he went on to make express reference to clause 1.6 of the Guidelines when considering the first accident and the injuries the plaintiff sustained to her cervical spine. Further, in Section 7 of his report headed "Determinations", he noted that the determination as to permanent impairment is made in accordance (inter alia) with "the Motor Accident permanent Impairment Guidelines 1 June 2018". It was not incumbent on the Assessor to make repeated express reference to the Guidelines when considering each aspect of the plaintiff's claims. It is sufficient if the Assessor's analysis accords with what the Guidelines set out. In this case the issue is whether the second accident could have caused or contributed to the worsening of the impairment, and a determination of whether it did so.
4. The Assessor's report makes it clear that he understood that the issues were those set out in clause 1.6 of the Guidelines. The whole basis of the Assessor's enquiry was to determine whether the second accident did cause or contribute to the worsening of the impairment. His frequent references, when reviewing the medical reports, to doctors finding that the second accident aggravated back symptoms, and to comparisons of the pre-accident and post-accident radiology, are a clear indication that the Assessor determined that the accident could have caused or contributed to the worsening of the back pathology.
5. However, on the Assessor's analysis of all of the material he had, and on his own clinical assessment, he determined that the accident did not cause or contribute to the worsening of the lumbar spine condition. That was the task the Guidelines dealt with.
6. No error is shown on this basis.

Conclusion

1. As the parties accepted, if error could not be identified in relation to the assessment by the third defendant, it followed that it cannot be shown in relation to the fourth defendant's refusal to refer the medical assessment to a Review Panel.
2. Accordingly, I make the following orders: 1. Extend time for the commencement of the proceedings to 30 June 2020. 2. Summons dismissed. 3. The plaintiff is to pay the first defendant's costs.

Amendments 05 August 2020 - Typographical error on cover sheet. 05 August 2020 - Typographical error on cover sheet. 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: 05 August 2020