Sawaneh v Flintwood Disability Services Ltd

BACKGROUND

1. The plaintiff is a 61-year-old woman who was formerly employed by the first defendant as a disability support worker.
2. On 10 April 2020, the plaintiff, in the course of her employment, slipped on a wet floor. As a result of this incident, the plaintiff alleged she sustained injuries to her left lower extremity (left knee) and lumbar spine and suffered scarring. She has since experienced ongoing pain and restricted movement.

The Claim before the Insurer

1. Following that incident the plaintiff lodged a claim with her employer's insurer, iCare, to obtain compensation for the injury of 10 April 2020. The types of compensation an injured employee is entitled to is governed by the Workers Compensation Act 1987 (NSW) (the "1987 Act"). In her claim before the insurer, the plaintiff sought payments for two heads of compensation available under that Act: 1. Weekly payments due to the plaintiff's total or partial incapacity to work following the injury (s 33 of the 1987 Act). 2. Compensation for costs associated with reasonable medical treatment arising from the plaintiff's injury (ss 59 and 60 of the 1987 Act).
2. Her claim was provisionally accepted on 4 May 2020 and the insurer commenced weekly payments to the plaintiff to compensate for the two types of loss alleged.
3. However, on 16 December 2020, iCare issued a Notice to the plaintiff in accordance with s 78 of the Workplace Injury Management and Workers Compensation Act 1998 (NSW) (the "1998 Act"). The s 78 Notice is a formal mechanism whereby an insurer notifies a claimant that it is disputing its liability to compensate.
4. iCare informed the plaintiff it was of the opinion she was not entitled to compensation for either of the two claimed heads of loss based on the following reasons: "Section 33 of the Workers Compensation Act 1987 provides if total or partial incapacity for work results from an injury, the compensation payable by the employer under this Act to the injured workers shall include weekly payment during the incapacity. … we dispute that you are entitled to compensation because we do not agree that your incapacity results from your injury on 10 April 2020 and therefore, you are not entitled to any weekly and medical compensation relating to your lumbar spine. We confirm you are not eligible for any ongoing or further medical or related treatment, hospital treatment and/or rehabilitation services as defined under Section 59 and Section 60 of the Workers Compensation Act 1987 as it is not reasonable and necessary as a result of a workplace injury."1
5. iCare informed the plaintiff that it would cease making any further payments from 12 January 2021.
6. The rejection of the plaintiff's entitlement to compensation was based upon the medical opinion of Dr Wallace, an orthopaedic surgeon. The substance of his opinion was described in the s 78 Notice as follows: "Dr Wallace further opined that your employment with Flintwood Disability Services ltd is not a substantial contributing factor to any of your current lumbar spinal condition and with regards to treatment you did not require any treatment for any work related condition of lumbar spine.… He confirmed that your current irritative L5 radiculopathy is due to pre-existing lumbar spondylosis at L4-5 which was constitutional in original and entirely unrelated to your employment." [1]
7. On 15 January 2021, the plaintiff sought an internal review of iCare's s 78 Notice. Although the reviewer agreed that the plaintiff was entitled to a slight adjustment to the date upon which payments would cease (which is not relevant to these proceedings), the ultimate position was maintained. Namely, iCare's rejection of any entitlement by the plaintiff to compensation because: "[her] current lumbar spinal condition is age-related degenerative lumbar condition and [she] suffer[s] no incapacity from [her] work related injury."

The Dispute is Brought Before the Personal Injury Commission

1. In addition to seeking internal review, the plaintiff also made an external application to the Personal Injury Commission of NSW (the "Commission") pursuant to s 288 of the 1998 Act. That application was a standard form document titled "Application to Resolve a Dispute". It sought to obtain resolution of the dispute between her and the first defendant with respect to entitlement to compensation.
2. The application was amended on 24 January 2022 by consent of the plaintiff and the first defendant. The pre-amended version of the s 288 application is not relevant to these proceedings.
3. The injury which was the subject of the application to the Commission (following amendment) was particularised in the following terms: Type of Injury: Personal Date of Injury: 10/04/2020 Injury Description / Cause of Injury and Death: In the course of employment the worker sustained injury to her left lumbar spine, left lower extremity (left knee) and scarring. Applicant slipped on wet floor and fell onto her left knee.
4. Further, the issues that both the first defendant and the plaintiff sought the Commission to resolve related to the plaintiff's entitlement to two forms of compensation under the 1987 Act. Notably, one of the forms of compensation now being disputed differs to the forms of compensation sought in the original claim before iCare. The two disputed heads of compensation before the Commission were as follows: 1. Whether the plaintiff was entitled to lump sum compensation based upon the degree of whole person impairment she suffered from the 10 April 2020 injury. If so, how much compensation was she entitled to by reference to the degree (percentage) of whole person impairment resulting from that injury. 2. Whether the plaintiff was entitled to weekly compensation due to her total or partial inability to work due to the 10 April 2020 injury.
5. Consideration of the second issue was postponed until after determination of the first issue. Further, the second issue was not before the Panel and is, therefore, not relevant to this judicial review which is the basis of the Amended Summons.

Referral by the Commission to a Specialist for Medical Assessment

1. To resolve the question of the degree of whole person permanent impairment, the Commission referred the case for medical assessment to Dr Mastroianni, the Medical Assessor, in accordance with ss 319 and 321 of the 1998 Act.
2. The procedural and substantive requirements of this medical assessment, as well as the subsequent appeal to the Panel, are all governed by legislation. Hence, it is helpful to first set out the statutory regime concerning medical disputes in the context of compensation for permanent impairment, prior to examining the actual decisions of the Medical Assessor and the Panel.

The Source of A Worker's Right To Recover For Permanent Impairment: The 1987 Act

1. Under the 1987 Act, a worker who has received an injury is entitled to receive compensation, in accordance with the Act, from their employer (s 9(1)). An injury is defined in s 4(a) as "a personal injury arising out of or in the course of employment".
2. Where that "personal injury" sustained has the quality of being permanent, one of the forms of compensation recoverable under the Act is for non-economic loss. Whether the worker is entitled to receive this type of compensation is determined in accordance with s 66 of the 1987 Act. That provision reads as follows: Division 4 Compensation for non-economic loss … 66 Entitlement to compensation for permanent impairment (1) A worker who receives an injury that results in a degree of permanent impairment greater than 10% is entitled to receive from the worker's employer compensation for that permanent impairment as provided by this section. Permanent impairment compensation is in addition to any other compensation under this Act. Note - No permanent impairment compensation is payable for a degree of permanent impairment of 10% or less.
3. The nature of workplace injuries captured by the operation of s 66 was examined by the Court of Appeal in Hunter Quarries Pty Ltd v Mexon (2018) 98 NSWLR 526; [2018] NSWCA 178. In that case, Sackville AJA, who concurred with the leading judgment of Payne JA, made the following observation at [107] (extracted so far as relevant): "[107] The expression "permanent impairment" consists of two words, one of which ("permanent") qualifies the other ("impairment"). The expression is not defined in the legislation. Although the expression is primarily associated with workers compensation entitlements, its use is by no means confined to that field. The expression in its ordinary usage connotes injuries or illnesses that have a significant debilitating effect on the person's physical capacities or quality of life for an indefinite period […]. (emphasis added).
4. Therefore, s 66, in effect, compensates where an injury sustained in the course of employment reduces a person's capacities or ordinary functioning indefinitely to a sufficient degree.

Procedure For Resolving Medical Disputes: The 1998 Act

1. Where there is a dispute between the worker and employer (as is the case here) concerning the degree of permanent impairment, if any, arising from a workplace injury, this is to be resolved in accordance with the procedure set out in Pt 7 of Ch 7 of the 1998 Act.
2. In summary, a "medical dispute" before the Commission (which included a dispute concerning the degree of permanent impairment: s 319) will be referred to a medical specialist (s 321). That specialist will then assess the degree of whole person impairment in accordance with s 322 (extracted here so far as relevant): 322 Assessment of impairment (1) The assessment of the degree of permanent impairment of an injured worker for the purposes of the Workers Compensation Acts is to be made in accordance with Workers Compensation Guidelines (as in force at the time the assessment is made) issued for that purpose. (2) Impairments that result from the same injury are to be assessed together to assess the degree of permanent impairment of the injured worker. (3) Impairments that result from more than one injury arising out of the same incident are to be assessed together to assess the degree of permanent impairment of the injured worker. … (4) A medical assessor may decline to make an assessment of the degree of permanent impairment of an injured worker until the medical assessor is satisfied that the impairment is permanent and that the degree of permanent impairment is fully ascertainable. Proceedings before a court or the Commission may be adjourned until the assessment is made.
3. The critical part of the Workers Compensation Guidelines ("the guidelines") which set out the applicable method for assessing the degree of impairment, per s 322(1), reads as follows: [2] PART 2 - PRINCIPLES OF ASSESSMENT 1.6 The following is a basic summary of some key principles of permanent impairment assessments: a. Assessing permanent impairment involves clinical assessment of the claimant as they present on the day of assessment taking account the claimant's relevant medical history and all available relevant medical information to determine: •whether the condition has reached Maximum Medical Improvement (MMI) •whether the claimant's compensable injury/condition has resulted in an impairment •whether the resultant impairment is permanent •the degree of permanent impairment that results from the injury •the proportion of permanent impairment due to any previous injury, pre-existing condition or abnormality, if any, in accordance with diagnostic and other objective criteria as outlined in these Guidelines. b. Assessors are required to exercise their clinical judgement in determining a diagnosis when assessing permanent impairment and making deductions for pre-existing injuries/conditions. c. In calculating the final level of impairment, the assessor needs to clarify the degree of impairment that results from the compensable injury/condition. Any deductions for pre-existing injuries/conditions are to be clearly identified in the report and calculated. If, in an unusual situation, a related injury/condition has not previously been identified, an assessor should record the nature of any previously unidentified injury/ condition in their report and specify the causal connection to the relevant compensable injury or medical condition. …
4. Importantly, and subject to the right of appeal, the medical assessment by the specialist is only allowed to be made once, per s 322A of the 1998 Act, as follows: 322A One assessment only of degree of permanent impairment … (3) Accordingly, a medical dispute about the degree of permanent impairment of a worker as a result of an injury cannot be referred for, or be the subject of, assessment if a medical dispute about that matter has already been the subject of - (a) assessment and a medical assessment certificate under this Part, or (b) a determination by the Commission under Part 4. (4) This section does not affect the operation of section 327 (Appeal against medical assessment) or 352 (Appeal against decision of Commission constituted by non-presidential member).
5. Furthermore, as indicated in the guidelines quoted above, pre-existing injuries are to be taken into account in a determination of the extent of whole person impairment: 323 Deduction for previous injury or pre-existing condition or abnormality (1) In assessing the degree of permanent impairment resulting from an injury, there is to be a deduction for any proportion of the impairment that is due to any previous injury (whether or not it is an injury for which compensation has been paid or is payable under Division 4 of Part 3 of the 1987 Act) or that is due to any pre-existing condition or abnormality. Importantly, where the deduction is likely to be "difficult or costly to determine", there is a default provision which favours imposing a deduction of 10%:(2) If the extent of a deduction under this section (or a part of it) will be difficult or costly to determine (because, for example, of the absence of medical evidence), it is to be assumed (for the purpose of avoiding disputation) that the deduction (or the relevant part of it) is 10% of the impairment, unless this assumption is at odds with the available evidence. Note - So if the degree of permanent impairment is assessed as 30% and subsection (2) operates to require a 10% reduction in that impairment to be assumed, the degree of permanent impairment is reduced from 30% to 27% (a reduction of 10%). (3) The reference in subsection (2) to medical evidence is a reference to medical evidence accepted or preferred by the medical assessor in connection with the medical assessment of the matter. […]
6. In conducting the assessment of the dispute, the assessor has the following powers: 324 Powers of medical assessor on assessment (1) The medical assessor assessing a medical dispute may - (a) consult with any medical practitioner or other health care professional who is treating or has treated the worker, and (b) call for the production of such medical records (including X-rays and the results of other tests) and other information as the medical assessor considers necessary or desirable for the purposes of assessing a medical dispute referred to him or her, and (c) require the worker to submit himself or herself for examination by the medical assessor.
7. After the assessment in accordance with s 322 of the 1998 Act, the Medical Assessor will then issue a Certificate pursuant to s 325 concerning permanent impairment (the "s 325 Certificate"). This Certificate is taken as conclusive evidence of, inter alia, the extent to which a person's functioning has been impaired and the degree the impairment is attributable to the referred injury: 326 Status of medical assessments (1) An assessment certified in a medical assessment certificate pursuant to a medical assessment under this Part is conclusively presumed to be correct as to the following matters in any proceedings before a court or the Commission with which the certificate is concerned - (a) the degree of permanent impairment of the worker as a result of an injury, (b) whether any proportion of permanent impairment is due to any previous injury or pre-existing condition or abnormality, […] (d) whether impairment is permanent, (e) whether the degree of permanent impairment is fully ascertainable. (2) As to any other matter, the assessment certified is evidence (but not conclusive evidence) in any such proceedings

AppeIg the Decision of Medical Assessor

1. It is possible to appeal the outcome of the first instance medical assessment, as outlined in the s 325 Certificate, to an Appeal Panel. However, the scope of the appeal is limited by operation of s 327 of the 1998 Act: 327 Appeal against medical assessment (1) A party to a medical dispute may appeal against a medical assessment under this Part, but only in respect of a matter that is appealable under this section and only on the grounds for appeal under this section. (2) A matter is appealable under this section if it is a matter as to which the assessment of a medical assessor certified in a medical assessment certificate under this Part is conclusively presumed to be correct in proceedings before a court or the Commission. (3) The grounds for appeal under this section are any of the following grounds - (a) deterioration of the worker's condition that results in an increase in the degree of permanent impairment, (b) availability of additional relevant information (but only if the additional information was not available to, and could not reasonably have been obtained by, the appellant before the medical assessment appealed against), (c) the assessment was made on the basis of incorrect criteria, (d) the medical assessment certificate contains a demonstrable error. …
2. The applicable procedure for the appeal process is set out in s 328, which empowers the Panel to either confirm the original decision, as evidenced on the s 325 Certificate, or revoke that decision and issue a revised one: 328 Procedure on appeal (1) An appeal against a medical assessment is to be heard by an Appeal Panel constituted by 3 persons chosen by the President as follows - … (2) The appeal is to be by way of review of the original medical assessment but the review is limited to the grounds of appeal on which the appeal is made. (2A) To avoid doubt, any medical re-examination of the worker for the purposes of the review need not be conducted by all of the members of the Appeal Panel if the members agree for it to be conducted by only some of the members. (3) Evidence that is fresh evidence or evidence in addition to or in substitution for the evidence received in relation to the medical assessment appealed against may not be given on an appeal by a party to the appeal unless the evidence was not available to the party before that medical assessment and could not reasonably have been obtained by the party before that medical assessment. … (5) The Appeal Panel may confirm the certificate of assessment given in connection with the medical assessment appealed against, or may revoke that certificate and issue a new certificate as to the matters concerned. Section 326 applies to any such new certificate. …

THE MEDICAL ASSESSMENT OF DR MASTROIANNI

1. In accordance with s 322 the Medical Assessor assessed the plaintiff on 9 March 2022 and issued a s 325 Certificate on 11 March 2022. His decision was based upon his own discussion with the plaintiff, a physical examination and numerous medical reports of other practitioners.
2. The Medical Assessor determined that the percentage of whole person impairment in each of the injured areas was 12% (lumbar spine), 4% (left knee) and 1% (scarring) respectively. However, with respect to the spine and knee injuries, he determined that one-tenth of the damage was attributable to "pre-existing injury, conditions or abnormalities" (see s 323(2)). Accordingly, the percentage of whole person impairment attributable solely to the 10 April 2020 incident was 11% (lumbar spine), 4% (left knee) and 1% (scarring), meaning the incident amounted to a total of 16% of whole person impairment.
3. The degree of permanent impairment is a reference to "whole person impairment", or the degree to which person has suffered a reduction in their total physical capacity, determined by reference to a prescribed formula, when all injuries flowing from the 10 April 2020 incident are viewed in combination. [3]
4. The Medical Assessor's findings are recorded in the Table attached to the s 325 Certificate, extracted below:
5. The Table along with six pages of discussion accompanied the findings. The substance of these six pages included a discussion of the available evidence; a discussion of the history relating to the injury; findings from the physical examination and details of investigations into the injury performed by other medical professionals. However, none of this discussion was ultimately relevant to the Panel's decision and, therefore, does not require repeating for the purpose of the Amended Summons. The relevant parts of the Medical Assessor's discussion which were critical to the appeal to the Panel are extracted in full below, in accordance with the order in which those sections appeared in the reasons attached to the s 325 Certificate.
6. First the Medical Assessor gave a summary of the injury in the following terms: 7. SUMMARY • summary of injuries and diagnoses: As a result of the fall Ms Sawaneh sustained injuries to the left knee and back, aggravating pre-existing asymptomatic patellofemoral arthritis and lumbar spondylosis and sustained a lumbar disc lesion. She had conservative treatment for the left knee and decompression surgery for the lumbar spine. • consistency of presentation She presents in a genuine manner and there were no inconsistencies.
7. The following "evaluation of permanent impairment" was given in accordance with the standard-form questions set out in the guidelines: 8. … a. Is the worker claiming for any body part/system outside your field of expertise? If so, please indicate the body par/system: No b. Have all body parts/systems stabilized/reached maximum medical improvement? Yes c. If not, please list those injuries not yet stable/at maximum medical improvement: Not applicable d. If stabilisation/maximum medical improvement, of any or all injuries has not been reached, when, in your opinion, will this occur? Not applicable e. Is any proportion of loss of efficient use or impairment or whole person impairment, due to a previous injury, pre-existing condition or abnormality? Yes f. If so, please indicate which body part/system is affected by the previous injury, pre-existing condition or abnormality. Lumbar spine and left knee.
8. The following reasoning was given to explain how the Medical Assessor had arrived at his conclusions or calculations concerning permanent impairment: 10. REASONS FOR ASSESSMENT a. My opinion and assessment of whole person impairment The claimant had a one-level decompression of the lumbar spine. She falls into DRE Lumbar Category 111<¹J (see 10b). ADLs are affected but she is independent in self-care regarding her back injury. I assess 12% whole person impairment. There is no evidence of radiculopathy. There is evidence of pre-existing lumbar spondylosis. In my opinion the pre-existing condition is a component of the current impairment. Being guided by the history of no previous injuries apart from an injury a year earlier at the same place of employment and the radiological findings which show facet arthropathy which was present prior to the 2019 incident when she had radiofrequency neurotomy, I have deducted one-tenth applying the provision of section 323. This equates to 1.2% WPI. She therefore has 10.8% WPI as a result of the injury which rounds off to 11%. She has 4% whole person impairment due to restricted flexion of the left knee. The left knee flexes to 100° which equates to 4% WPI. There is evidence of pre-existing degenerative disease in the knee. I have deducted one-tenth applying the provision of section 323. This equates to 0.4% WPI. She therefore has 3.6% WPI as a result of the injury which rounds off to 4% WPI. I assess 4% WPI for the left knee due to restricted range of movement. She has left knee chondromalacia patellae which equates to 2% WPI<2J (see 10b). The two impairments cannot be combined<3J (see 10b). I have therefore given the claimant the higher impairment. There is scarring which under the best-fit principle of the TEMSKI classification falls into the 1% WPI category. b. An explanation of my calculations (if applicable) AMA Guides to the Evaluation of Permanent Impairment, 5ᵗʰ Edition: (1) Page 384, Table 15-3. (2) Page 544, Table 17-31. (3) Page 526, Table 17-2. Worksheet /actual calculations attached? No. (emphasis added).
9. In the "reasons for assessment" section, the Medical Assessor also commented on the medical opinions of other doctors who had reviewed the plaintiff, as follows: c. My brief comments regarding the other medical opinions and findings submitted by the parties and, where applicable, the reasons why my opinion differs I note the report of Dr E Gehr dated 25 June 2021. I found the same DRE Category as Dr Gehr. He assesses post-operative radiculopathy. On examination I found normal neurology and could not reproduce his findings. He makes no deduction for pre-existing condition. In my opinion a deduction is applicable (see 10a). I found the same impairment for restricted flexion in the knee. I found normal extension and I could not reproduce the flexion contracture found by Dr Gehr. He makes no deduction for pre-existing condition. A deduction in my opinion is applicable (see 10a). I note the reports of Dr Raymond Wallace dated 29 September 2020 and 17 December 2021.I found the same impairment as Dr Wallace for the lumbar spine and the scar. I found a rateable impairment for the left knee. The doctor attributes the impairment to pre-existing condition. I have addressed pre-existing condition under 10a.
10. The last point of the "reasons for assessment" section, involved affirming that "the impairment is permanent and that the degree of permanent impairment is fully ascertainable".
11. Also of note was the deduction for pre-existing injuries or conditions, which was already briefly touched upon in the "reasons for assessment" section of the Certificate. It read as follows: "11. DEDUCTION (IF ANY) FOR THE PROPORTION OF THE IMPAIRMENT THAT IS DUE TO PREVIOUS INJURY OR PRE-EXISTING CONDITION OR ABNORMALITY The worker has evidence of underlying degenerative disease of the lumbar spine and the left knee. In my opinion, persistent symptoms in the back and knee are the result of injury sustained at work and the underlying degenerative disease. I am of the opinion that the pre-existing degenerative disease is a component of the current impairment. I have deducted (1/10) as outlined in 10a applying the provisions of s323(2) as the extent of the deduction is difficult or costly to determine.
12. The last sentence of the above extract demonstrates the Medical Assessor opted to apply the default statutory deduction of 10%, pursuant to s 323(2), in circumstances where he believed that taking into account the degree of impairment attributable to earlier injuries/conditions was difficult to ascertain.

THE FIRST DEFENDANT'S APPEAL AGAINST THE MEDICAL ASSESSOR'S DECISION TO THE PANEL

1. In accordance with ss 327(c) and (d), the first defendant appealed to the Panel on the following grounds: a. The assessment by the Medical Assessor was made on the basis of incorrect criteria. b. The medical assessment certificate contains a demonstratable error.
2. These grounds were supplemented with the following particulars: a. In accordance with the terms of reference to the MA, the impairment assessment must be confined solely to the subject personal work incident dated 10 April 2020. b. The MA, in error, included in his impairment assessment the impairment arising from an earlier 2019 injury. c. The MA therefore failed to appropriately deduct under section 323 of the 1998 Act the proportion of the impairment due to any previous injury d. The MA also incorrectly applied section 323(2) of the 1998 Act and in so doing, failed to appropriately deduct the proportion of the impairment due to a pre­ existing condition or abnormality. 6. In those circumstances, the appellant submits the assessment by the MA was made on the basis of incorrect criteria and/or the MAC contains a demonstrable error.
3. Hence, it is apparent that the critical error in the Medical Assessor's decision, from the perspective of the first defendant, was taking into account the 2019 injury in combination with the 10 April 2020 injury in determining the degree of permanent impairment under s 322 for which the first defendant was to be held liable. In essence, it was contended that, because the Medical Assessor recognised the 2019 incident as "an injury a year earlier at the same place of employment", the Medical Assessor presumed it was permissible to similarly hold the first defendant responsible for the damage of this incident as well. However, the first defendant contended this was beyond the permissible scope of the assessment by the Medical Assessor, charged solely with the responsibility of determining the degree of whole person impairment which arose solely from the 10 April 2020 incident.
4. Furthermore, the first defendant suggested that the Medical Assessor, in doing so, erred because, in viewing the 2019 incident in combination with the 10 April 2020 incident, this meant the deduction under s 323 was not applied correctly. This is because no deduction was given to account for the extent of pre-existing damage that was attributable to the 2019 incident that was not the subject of the referral, despite s 323 mandating that course.

THE REVIEW OF THE MEDICAL ASSESSOR'S DECISION BY THE PANEL

1. The Panel's decision commenced with a brief summary of the procedural history and a statement to the effect that it was satisfied that at least one of the grounds of appeal had been made out.
2. Next, various preliminary matters were addressed, including the Panel's decision that it did not believe it necessary to conduct another medical examination of the plaintiff, despite error having been demonstrated, as the material before it was sufficient to make a new determination.
3. Other preliminary matters included observing that the evidence before it was identical to what was before the Medical Assessor and that it had taken such evidence into account. The Panel also stated that the parties' written submissions "are not repeated in full [in the reasons], but have been considered" and re-stated the grounds and particulars of the appeal (set out at [45]-[46] above).
4. The Panel then recited the Medical Assessor's decision in its entirety (which need not be repeated).
5. The Panel then gave reasons to the effect that the appeal was allowed as the Medical Assessor had erred. It was of the opinion the amount deducted for under s 323 was "at odds" with the available evidence. In the result, the Panel reissued a decision on that basis. The reasons for this were as follows: "24. A s 323 deduction can only be made if the pre-existing injury, condition or abnormality has contributed to the level of permanent impairment assessed. The MA deducted one-tenth for the reasons he gave above. The appellant complains on appeal that he has not deducted the proportion related to a previous injury in 2019 and instead has improperly taken this injury into account with the overall assessment of impairment as a result of the injury referred to him being 10 April 2020. In addition, the appellant complains on appeal that the MA has failed to take proper account of the pre-existing condition or abnormality of the lumbar spine. 25. The Appeal Panel after a careful review of the evidence considers that the MA has erred. 26. The respondent worker suffered an injury to her back in 2019. She was referred for a CT scan of the lumbar spine on 20 June 2019. This investigation was not referred to by the MA. This investigation records a clinical history of "lumbar radicular pain on the right". The findings are reported as follows: "Mainly facet arthropathy noted, worse at L4-5 but also affects L3-4 and L5-S1. There is also moderate broad based disc protrusion at L4-5, but no canal foraminal [(sic] narrowing or nerve impingement is seen. There is sacroiliac joint arthropathy, worse on the left with cystic change." 27. What this means is that the respondent worker had chronic underlying degenerative changes in her lumbar spine which were aggravated by the injury in 2019 (not the subject of the referral). 28. After the fall on the 10 April 2020, the respondent worker was referred for a MRI investigation which took place on 18 June 2020 and was reported 19 June 2020. The clinical history is recorded as "pain radiating to under right side of heel". The findings are recorded as follows: "No fracture. No focal disc herniation. Localised advanced spondylitic changes at L4/5 level with significant degeneration and vacuum phenomenon. The disc bulge is abutting the origin of the L5 nerves in the lateral recess without compression. Severe erosive arthropathy in the L4/5 and L5/S1 facet joints worse on the right side." 29. What this means is that the respondent worker had chronic underlying degenerative changes in her lumbar spine which were aggravated by the injury in 2019 (not the subject of the referral) and again on 10 April 2020 (the subject of the referral). 30. The chronicity of the changes shown on the radiological investigations is consistent with the general practitioner's (GP) clinical record of a "history of intermittent back pain treated in the past" in the certificate of capacity issued by Dr Qidwai dated 26 October 2020. 31. After the injury on 10 April 2020 the respondent was not successfully able to return to work, symptoms persisted and she came to surgery at L4/L5. 32. The assessment of overall permanent impairment is DRE II (10% whole person impairment (WPI) plus 2% WPI for activities of daily living (ADLs)) based on the surgery and the overall level of permanent impairment is not the subject of complaint on appeal. 33. The contribution of the pre-existing condition, abnormality or injury to the overall level of permanent impairment must be taken into account. 34. On the available evidence, the pre-existing condition of the lumbar spine is able to be demonstrated by the CT investigation of 20 June 2019 and the MRI investigation of 18 June 2020. 35. The CT investigation of 20 June 2019 demonstrates facet arthropathy and disc protrusion at L4/5. 36. The MRI investigation of June 2020 demonstrates severe erosive arthropathy in the L4/54 and L5/5S1 facet joints worse on the right side." 37. The severe erosive arthropathy demonstrated in the L4/5 and LS/S1 facet joints does not result from injury on 10 April 2020 but is a pre-existing condition which was aggravated by the injury. The pre-existing condition demonstrated by the radiological investigations, the injury in 2019 and the injury in 2020 have all contributed to the need for surgery on which the assessment of permanent impairment is based. 38. Account must be taken of the contribution of the pre-existing injury (in 2019) and the pre­existing condition and abnormality of the lumbar spine demonstrated on the radiological investigations to the level of permanent impairment assessed as a result of injury on 10 April 2020 (being the referred date of injury). The available evidence is at odds with a deduction of one-tenth. Rather, the available evidence supports a deduction of one-half." (emphasis added)
6. Based on this finding of error and that that greater weight needed to be attributed to already damaged condition of the lumbar spine which existed prior to the 10 April 2020 incident, the Panel issued a new Certificate:
7. The effect is that, after taking into account any "deduction[s] for previous injury or pre-existing condition or abnormality", in accordance with s 323 of the 1998 Act, the Panel determined that the degree of permanent injury solely referable to the 10 April 2020 incident became 6% (lumbar spine), 4% (left knee) and 1% (scarring) respectively. Therefore, the degree of whole person impairment when the three injuries were considered in combination was 11%. This amounted to a 5% reduction of the original percentage proposed by the Medical Assessor of 16%. The outcome being that the extent of non-economic loss damages recoverable by the plaintiff from the first defendant/insurer by reason of suffering permanent impairment would be considerably reduced.

PROCEDURAL HISTORY AND CHANGES TO THE GROUNDS OF THE SUMMONS

1. Prior to outlining the grounds for judicial review of the Panel's decision, it is important to note there was some procedural complexity involved in refining the grounds of the Amended Summons. The history of such can be conveniently summarised as follows.
2. The original Summons was filed on 15 November 2022 seeking judicial review of the Panel's decision. The plaintiff's grounds for disputing that decision were articulated in the following terms: 1 Jurisdictional error or in the alternative a constructive failure to exercise jurisdiction by engaging conduct whereby the second defendant did not meaningfully engage with the opposition to the appeal and the submissions made by the plaintiff in writing. 2 Denying the plaintiff procedural fairness in determining the deductions made pursuant to s 323 of the Workplace Injury Management and Workers Compensation Act 1998 (NSW) without adequate reasoning or any reasoning. 3 Committing an error of law on the face of the record by determining issues of causation being issues that were beyond the jurisdiction of the Second Defendant. 4 Committing an error of law on the face of the record in the determination by the Second Defendant and methodology undertaken by it for the purposes of a deduction pursuant to s 323 of the Workplace Injury management and Workers Compensation Act 1998 (NSW).
3. The plaintiff sought a declaration pursuant to s 69 of the Supreme Court Act 1970 (NSW) with an order in the nature of certiorari that the Panel's decision is void and of no effect. The plaintiff also sought an order setting aside the Panel's decision and remitting it back to a differently constituted Medical Appeal Panel according to law.
4. As became apparent in the first hearing for this matter on 28 June 2023, the grounds of appeal set out in the original Summons required amendment.
5. First, the Court raised with the plaintiff that Ground 3, as it appeared in the Summons, required rearticulating as it "fell short" of accurately capturing the "purport" of the oral argument being put forward by the plaintiff.
6. The other difficulty in Ground 3 was its mischaracterisation of the appropriate cause of action. It was expressed as an error of law on the face of the record. However, the flaw that Ground 3 sought to address was that the Panel's findings were "beyond the power of a medical appeal panel to adjudicate upon". Therefore, the error alleged is a jurisdictional one, whereby the Panel exceeded the powers granted to it by the Parliament, through the 1998 Act: see Craig v South Australia (1995) 184 CLR 163, at 179 (Brennan, Deane, Toohey, Gaudron and McHugh JJ).
7. After these shortfalls were raised with the plaintiff during the hearing, the plaintiff sought leave to amend that ground. The proposed Amended Summons was received by the Court on 5 July 2023. The newly drafted version of Ground 3 was in the following terms: "3 Committing a jurisdictional error by forming an opinion [27]-[30] as part of the formation of the opinion as to whole person impairment and correcting error, by concluding that the plaintiff suffered aggravations from 2 unreferred injuries being opinions as to liability which was beyond the jurisdiction of the Medical Appeal Panel."
8. Following receipt of the proposed amendment, a second hearing was conducted on 14 July 2023 to ascertain the suitability of the revised articulation of Ground 3. The defendant agreed to the amendment provided, leave was granted by the Court to enable both the plaintiff and the first defendant to develop supplementary written submissions, limited to arguments in support of the newly drafted Ground 3. Leave was granted on that basis. Those submissions were made in writing and orally. They are reflected in the summary of submissions below.
9. With respect to the other three grounds (see [57] above), Grounds 1 and 2 remained unchanged. However, counsel for the plaintiff advised Ground 4 was no longer pressed and, therefore, will not be considered in this judgment.

DISPOSITION OF THE APPEAL

1. I shall deal with each ground of appeal seriatim.

Ground 1: Jurisdictional Error or In The Alternative A Constructive Failure To Exercise Jurisdiction By Engaging Conduct Whereby The Second Defendant Did Not Meaningfully Engage With The Opposition To The Appeal And The Submissions Made By The Plaintiff In Writing.

The Plaintiff

1. The plaintiff based this ground of appeal upon how the Panel dispensed with the plaintiff's submissions.
2. First, instead of attempting to explain what the plaintiff's arguments were, in the form of some summary or the like, the Panel simply noted that submissions of the parties "are not repeated in full, but have been considered."
3. Beyond this, the only discussion of the plaintiff's arguments that appeared throughout the Panel's decision was to state the obvious, namely, that the plaintiff did not agree with either of the first defendant's grounds of appeal (which are outlined at [45] above): "In summary, the respondent worker [plaintiff] submitted that the MA did not err or make an assessment on the basis of incorrect criteria and accordingly the [s 325 certificate] should be confirmed."
4. Based upon this very limited engagement, it was submitted that the "appeal panel has [not] responded" to any of the plaintiff's "clearly articulated arguments based on the established facts." The plaintiff gave the example that the Panel did not address in any substantive way her submissions on causation, which, relevantly, is now the focal point of Ground 3 in this Summons.
5. This was contrasted with the attention given to the first defendant's arguments before the Panel, as alleged by the plaintiff in oral submissions: "They dealt with what was required by the First Defendant, but they simply noted what was put by my client."
6. In failing to respond to the plaintiff's "clearly articulated arguments", it was contended that this amounted to a failure to make an assessment which grappled with the substantive case presented before it, and in turn, a constructive failure of the Panel to perform its statutory task.
7. In support of this argument the plaintiff cited Dranichnikov v Minister for Immigration and Multicultural Affairs (2003) 214 CLR 496; [2003] HCA 26 ("Dranichnikov"), where Gummow and Callinan JJ said the following in determining that there had been a constructive failure to exercise jurisdiction (at [24]): "[24] 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. A failure to accord natural justice did not provide a statutory basis for a review of a decision of the Tribunal."
8. The plaintiff also cited a similar passage in Re Minister for Immigration and Multicultural Affairs; Ex parte Miah (2001) 206 CLR 57; [2001] HCA 22 ("Ex Parte Miah") at [81], where Gaudron J said words to a similar effect: "[81] However, the present case is, in my view, a clear case of constructive failure to exercise jurisdiction. That is because the delegate failed to consider the substance of Mr Miah's application and could only have failed to do so because he misunderstood what is involved in the Convention definition of 'refugee'."

The First Defendant

1. Despite the limited degree of engagement with the plaintiff's arguments by the Panel, the defendant submitted that the Panel's reasons considered all essential matters for determination and, therefore, there was no constructive jurisdictional failure.
2. The defendant emphasised that interpreting the rule in Dranichnikov too broadly is not without consequence. Assessing whether and to what extent an executive decision maker grapples with each argument made before it encroaches on an investigation into the merits of the decision: Ming v Director of Public Prosecutions (NSW) [2022] NSWCA 209 (per Kirk JA at [15]) ("Ming").
3. In order for the failure to address an argument to mean that there has been a constructive failure to exercise its jurisdiction, that argument "must be of such significance as to warrant a conclusion that the decision-maker has failed to complete the exercise of its power": Ming at [15] (Kirk JA).
4. The defendant opined that the only issue of importance put forward by the plaintiff in her submissions to the Panel was the submission that the Medical Assessor's reasoning was correct, and therefore, the original s 325 Certificate should stand. The defendant alleged this issue was addressed simply by the way that the Panel set out the Medical Assessor's decision at length and outlined why it was wrong: "It is not necessary to review the appeal panel's reasons with an eye keenly attuned to error, the position taken by the worker below was that the medical assessor's decision was right, and so the appeal panel referred at length to the decisions of the medical assessor, but the fact that each paragraph refers to submissions below is not individually stated doesn't reveal any lack of engagement…"
5. On this basis, the defendant submitted that there was no constructive failure to exercise jurisdiction.

Consideration Ground 1

1. The plaintiff relied upon passages from the High Court decision of Dranichnikov and Ex Parte Miah to advance the contention of constructive failure to exercise jurisdiction failure by reason of the Panel's non-engagement with the plaintiff's submissions.
2. Dranichnikov involved judicial review of a decision of the Refugee Review Tribunal where a Russian citizen sought a protection visa under the Migration Act 1958 (Cth). In order to obtain such he was required to demonstrate to the Tribunal that he was a refugee in accordance with the Convention Relating to the Status of Refugees (entered into force 22 April 1954), namely, he had to demonstrate that he had "[a] well founded fear of prosecution [in Russia] for reason of … membership of a particular social group". In an application for prerogative relief pursuant to s 75(v) of the Constitution 1901 (Cth), the High Court determined that the Tribunal's reasons demonstrated a constructive failure to exercise the jurisdiction conferred under the Migration Act.
3. The basis of this finding was that the Tribunal misconstrued the applicant's submissions with respect to the social group to which he belonged. The Tribunal found the group to which the applicant belonged was 'business people', and this was no basis for qualifying for refugee status as the Tribunal "did not accept that there is evidence to suggest there is general persecution of businessmen in Russia". However, the High Court determined this failed to address his actual concern, in that not only was he a member of the business community, but a subset of that community who engaged in public protest against state sanctioned corruption and organised crime. Therefore, the submission that went to the heart of the issue before the Tribunal was misconstrued.
4. Ex Parte Miah similarly involved an application for a protection visa, although concerning a Bangladeshi citizen. The mistake which gave rise to a constructive jurisdictional failure was that the delegate to the Minister of Immigration, as evidenced on the reasons given, misunderstood the permissible considerations relevant to an assessment as to whether Mr Miah "had a well-founded fear of persecution" (Gleeson CJ and Hayne J at [1]).
5. The delegate did not engage with the submissions put forward by the applicant in explaining why he, personally, had a well-founded fear of being subjected to persecution, namely, because he himself had been the target of historical attacks by Islamic fundamentalists.
6. By failing to consider such submissions Gleeson CJ, Gaudron J, McHugh J, Kirby J, Hayne J inferred the delegate misunderstood that circumstances peculiarly effecting an individual, not necessarily shared by other members of society, could be a relevant consideration to the assessment of refugee status: "[86] The delegate constructively failed to exercise jurisdiction in this matter because he failed to appreciate that the Convention definition of "refugee" looks both to the individual and to the circumstances prevailing in his or her country of nationality. In consequence, the delegate failed to treat Mr Miah's application as one in which he claimed to have been individually targeted by Jamat-I-Islam."
7. Both these cases reflect the substance of what amounts to a constructive failure to exercise jurisdiction, as observed by Gaudron J in Ex Parte Miah at [80] (footnotes omitted): "[80] The classic statement as to what constitutes constructive failure to exercise jurisdiction is that of Jordan CJ in Ex parte Hebburn Ltd; Re Kearsley Shire Council. That statement, which has been approved by this Court on numerous occasions identifies a constructive failure to exercise jurisdiction as occurring when a decision-maker "misunderstand[s] the nature of the jurisdiction which [he or she] is to exercise, and ... appl[ies] 'a wrong and inadmissible test' ... or ... 'misconceive[s his or her] duty,' ... or '[fails] to apply [himself or herself] to the question which the law prescribes' ... or '... misunderstand[s] the nature of the opinion which [he or she] is to form'"." (emphasis added).
8. It follows that in order to determine whether or not the Panel has misunderstood or misapplied its powers such that a constructive jurisdictional failure has occurred, it is necessary to construe the relevant provisions of the 1998 Act which outline the task the Panel was required to perform.
9. Prior to embarking on this enquiry, however, it should be emphasised that, plainly, the plaintiff's submissions failed to adequately grapple with the statements in Dranichnikov and Ex Parte Miah. In effect, the plaintiff argued there was a constructive failure where the Panel did not engage with each of her submissions adequately because they were "simply noted". However, this wrongly conflates the principles in Dranichnikov and Ex Parte Miah with some box-ticking exercise. The only real issue is whether, by not sufficiently engaging with a submission on behalf of the plaintiff, the Panel in turn misunderstood, misapplied of failed to exercise the power conferred upon it under the statute.
10. The provisions of the 1998 Act applicable to the Panel's decision in this case may be summarised as follows. A determination of a Medical Assessor, encapsulated in a s 325 Certificate and accompanying reasons (325(2)(c)), is appealable to the Panel solely on the grounds listed under s 327(3) and only concerning findings of the Medical Assessor which are "conclusively presumed to be correct" in later proceedings, listed under s 326 (see s 327(2)). further, the scope of the review made by the Panel is "limited to the grounds of appeal on which the appeal is made" (328(2)). Finally, the Panel can either "confirm the certificate of assessment" or "revoke that certificate and issue a new certificate" (s 328(5)).
11. Here, the grounds of appeal elected in accordance with s 327(3) were twofold. First, that the assessment was made on the basis of incorrect criteria, and, secondly, the medical certificate contained demonstrable error. The finding "conclusively presumed to be correct" being disputed, was the Medical Assessor's finding concerning the "degree of permanent impairment […] as a result of an injury" which was calculated having regard to deductions for any "proportion of permanent impairment is due to any previous injury or pre-existing condition".
12. In light of the provisions summarised briefly above, there would be no constructive failure to exercise jurisdiction if the Panel met the following requirements, as evidenced by the reasoning it gave attached to the reissued s 325 Certificate: 1. Correctly turned its mind to and understood these two grounds concerning demonstrable error and incorrect criteria infecting the Medical Assessor's decision with respect to the appropriate deduction. 2. Did not consider any other grounds upon which the Medical Assessor could have erred in its review. 3. Understood the submissions of the parties which went to the heart of these grounds. 4. Gave an opinion concerning the validity of the Medical Assessor's deduction based upon the grounds of error as alleged. 5. Either affirmed the original s 325 Certificate or revoked the Certificate and reissued a new Certificate based upon the antecedent decision of whether or not the Medical Assessor erred.

Conclusion with respect to Ground 1

1. Before the Panel, the heart of the defendant's allegation of error was that the Medical Assessor improperly included the 2019 incident, being another injury also sustained during the same tenure of employment, in making the finding with respect to the degree of the whole person impairment that the employer (and therefore the insurer) was liable to compensate for (16% after the deduction). This was despite the fact that the 2019 incident was not the injury which was the subject of the referral. It was submitted that in so taking the 2019 incident into account for the purpose of this assessment, the finding of degree of permanent impairment "as a result of" the referred injury, was incorrect.
2. The plaintiff sought to contradict this submission by alleging that the Medical Assessor was required to consider the 2019 injury in applying the s 323 deduction, and, therefore, "any assertion by the appellant that the Medical Assessor erred by assessing the impact of the previous 2019 injury […] is inconsistent with the assessment required by s 323".
3. This is the substantive contest that was before the Panel which required resolution such that the Panel would deliberate on the grounds of the appeal in proper exercise of its statutory task.
4. In my view, nothing from the Panel's reasons demonstrate a misunderstanding, misapplication or failure to perform an element of the statutory task it was required to perform by virtue of some failure to engage with the plaintiff's submissions on this point or any other. In substance, it was the plaintiff who seemed to be under a misapprehension with respect to what task the Medical Assessor was required to perform.
5. The plaintiff misconstrued the (correct) argument put forward by the defendant to the Panel. It failed to appreciate the fundamental distinction between the Medical Assessor considering the impact of the 2019 incident for the purpose of making a deduction, as required under s 323, as opposed to the Medical Assessor impermissibly taking into account the 2019 incident jointly with the referral injury in assessing the degree to which the employer should be held liable to compensate for whole person impairment.
6. In other words, the 2019 incident was only permitted to be considered by the Medical Assessor so far as it was relevant to making a deduction, or reducing the degree of liability of the employer, in making a finding that a certain degree of the impairment to the lumbar spine could not be a result of the referral incident, because it was caused by the 2019 incident.
7. The 2019 incident could not be considered jointly with the referral incident, notwithstanding that it may have also occurred whilst the plaintiff was working for the defendant as a disability support worker. The effect of that was that it would be holding the employer liable to compensate the plaintiff for a proportion of impairment to the lumbar spine that was caused by an incident that the Commission has not previously found arose "out of or in the course of [the plaintiff's] employment", giving rise to liability of the employer (ss 4 and 9 of the 1987 Act).
8. The acceptance of the first defendant's argument on this point, and the implicit rejection of the plaintiff's, was articulated in the following statement of the Panel's reasons: "The MA deducted one-tenth for the reasons he gave above. The appellant complains on appeal that he has not deducted the proportion related to a previous injury in 2019 and instead has improperly taken this injury into account with the overall assessment of impairment as a result of the injury referred to him being 10 April 2020. […]. The Appeal Panel after a careful review of the evidence considers that the MA has erred."
9. In circumstances where the critical argument of the plaintiff before the Panel amounted to a mischaracterisation of the Medical Assessor's function, not addressing the plaintiff's submission, can be taken to simply be seen as a recognition of the fact that the plaintiff's argument in this respect was so clearly lacking in merit that it did not require rebuttal. In any event, there can be no misunderstanding of the Panel's proper exercise of statutory power here, by virtue of not responding to a submission, when that submission was misplaced.
10. There is no constructive failure to exercise jurisdiction. The ground is dismissed.

Ground 2: Denying the Plaintiff Procedural Fairness in determining the Deductions made pursuant to s 323 Of The Workplace Injury Management And Workers Compensation Act 1998 (NSW) without Adequate Reasoning or any Reasoning

The Plaintiff

1. The plaintiff alleged that the Panel's reasoning, which sought to justify the revised deduction of one-half to account for pre-existing injuries pursuant to s 323, was inadequate.
2. The basis of this submission was that the Panel considered the existence of prior injuries and/or conditions and then went straight on to presume that these pre-existing injuries warranted deduction. The Panel then made the finding that "the available evidence is at odds with a deduction of one-tenth. Rather, the available evidence supports a deduction of one-half."
3. The plaintiff contended that, in doing so, no actual methodology was put forward which outlined why that proportion of the deterioration to the lumbar spine was more appropriate than the original proportion put forward by the Medical Assessor.
4. Furthermore, the plaintiff emphasised that the Panel failed to comply with judicial statements advanced in cases like Ryder v Sundance Bakehouse & Tea Rooms [2015] NSWSC 526 at [45] ("Ryder"). Campbell J in Ryder said that what was required under s 323, in applying a deduction, was that the Panel needs to demonstrate that the plaintiff's injury to her lumbar spine would not have been as great but for the pre-existing condition. Otherwise, it is not possible to say that some degree of the impairment is attributable to the pre-existing injury. Counsel for the plaintiff made the following written submission: "What s 323 required was an inquiry into whether there were other causes involved of an impairment caused by work injury. A proportion of the impairment would be due to pre-existing abnormality but only if it can be said that the pre-existing abnormality made a difference to the outcome in terms of the degree of impairment resulting from the work injury. If there is no difference in outcome, that is to say if a degree of impairment is not greater then it would have otherwise been as a result of the injury, it is impossible to say that a proportion of it is due to the pre-existing abnormality. Put differently, the panel must be satisfied that but for the pre-existing abnormality the degree of impairment resulting from the work injury would not have been as a great. It is not enough to simply identify that there was a pre-existing condition with a subsequent impairment and therefore make a deduction because of the existence of a pre-existing condition. This would fail to consider the critical step that a proportion of the permanent impairment is due to the pre-existing condition. […] At a very minimum the panel had to give some explanation for its preference of one conclusion over the other and in this case the counter-factual put by the plaintiff was not addressed."

The First Defendant

1. The first defendant agreed with the submission that the Panel was required to demonstrate a difference of outcome to the damage to the lumbar spine in the absence of the pre-existing condition. It accepted that the decisions of Ryder at [45] and Bos v East Coast Security Dogs Pty Ltd [2022] NSWSC 1282 at [39] were good authority.
2. However, the effect of the defendant's argument was that a finding of a "difference of outcome" was implied in the Panel's reasoning, which noted that the subsequent injuries had an aggravating effect on the degenerative condition of the lumbar spine.
3. Finally, the defendant emphasised that the requisite degree of reasoning necessary, where the Panel is basing its decision on expert medical opinion, is not a high threshold to surpass. It relied upon the decision of Basten AJ in Lancaster v Foxtel Management Pty Ltd [2022] NSWSC 929 at [45] ("Foxtel Management"): "[45] [the purpose of the obligation to give reasons] is to ensure that, to the extent possible, any error of law in the reasoning of the Appeal Panel is revealed and may be the subject of an application for judicial review. However, as a practical matter, the Appeal Panel is likely to determine the question before it as a matter of expert medical opinion, the basis for which is peculiarly a matter of its special expertise and which will rarely give rise to any error of law, except on the basis that it is devoid of support in the material before the panel."

Consideration Ground 2 - Insufficient Reasons

1. As is clear from the plaintiff's submissions, this ground concerned a contention as to inadequate reasoning. Those submissions were directed to how the Panel exercised its power in accordance with s 328(5), namely, deciding to revoke the original s 325 Certificate, which provided for a deduction of one-tenth for any "previous injury or pre-existing condition or abnormality" and issue a new one with a revised deduction of one-half.
2. Unlike the original assessment of the Medical Assessor, there was no express statutory obligation for the Panel to give reasons when making this assessment afresh. Nonetheless, an obligation arises at general law, and the scope of this obligation is captured by what the High Court said in Wingfoot Australia Partners Pty Ltd v Kocak (2013) 252 CLR 480 ("Wingfoot"): see Foxtel Management at [45].
3. Further, the application of the decision in Wingfoot to a decision made by a Medical Appeal Panel exercising its powers under Pt 7 Ch 7 of the 1998 Act (as has occurred here) was considered in Campbelltown City Council v Vegan (2006) 67 NSWLR 372; [2006] NSWCA 284 ("Campbelltown City Council") and Foxtel Management.
4. In Wingfoot the High Court (French CJ, Crennan, Bell, Gaegler and Keane JJ) said the following at [54] and [55]): "[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. [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."
5. Further, Basten JA said the following in Campbelltown City Council at [121]: "[121] More importantly, where more than one conclusion is open, it will be necessary for the Panel to give some explanation of its preference for one conclusion over another. That aspect may have particular significance in circumstances where the medical members of a Panel have made their own assessment of the applicant's condition and have come to a different conclusion from that reached by other medical practitioners, as set out in reports provided to the Panel."
6. However, as was noted by Basten AJ in Foxtel Management, the extent of the obligation to give reasons will typically be less onerous where such decisions are based upon medical expertise: "[45] … That purpose [to give reasons] is to ensure that, to the extent possible, any error of law in the reasoning of the Appeal Panel is revealed and may be the subject of an application for judicial review. However, as a practical matter, the Appeal Panel is likely to determine the question before it as a matter of expert medical opinion, the basis for which is peculiarly a matter of its special expertise and which will rarely give rise to any error of law, except on the basis that it is devoid of support in the material before the panel." (emphasis added).
7. Based upon these authorities, the plaintiff's submission that the Panel's decision to reverse the original deduction of one-tenth and impose a one-half deduction in lieu lacked adequate reasoning is plainly wrong for the following reasons:
8. First, I do not agree that the Panel failed to provide any explanation for its preference of one conclusion (being the one-half deduction) over another (the default one-tenth deduction) and therefore did not meet the requirement articulated in Campbelltown City Council at [121].
9. The Panel noted how a 2019 CT scan was "not referred to by the MA" in his reasons, although the Panel relied upon this scan extensively in its opinion. This is despite the fact that such evidence would have been before the MA, as the brief of evidence was identical.
10. The fact that the Panel considered different parts of the evidence when forming its opinion is significant because it provides a rational basis upon which the Panel thought it was appropriate to depart from the original decision of the MA. As will become evident, this 2019 CT scan was fundamental to the different opinion held.
11. Secondly, the plaintiff emphasised that there was a mistake akin to that of the one in Ryder, where the following was said concerning the lack of reasons in applying a deduction in accordance with s 323 (extracted again for ease of reference): "[45] What s 323 requires is an inquiry into whether there are other causes, (previous injury, or pre-existing abnormality), of an impairment caused by a work injury. A proportion of the impairment would be due to the pre-existing abnormality (even if that proportion cannot be precisely identified without difficulty or expense) only if it can be said that the pre-existing abnormality made a difference to the outcome in terms of the degree of impairment resulting from the work injury. If there is no difference in outcome, that is to say, if the degree of impairment is not greater than it would otherwise have been as a result of the injury, it is impossible to say that a proportion of it is due to the pre-existing abnormality. To put it another way, the Panel must be satisfied that but for the pre-existing abnormality, the degree of impairment resulting from the work injury would not have been as great."
12. In application of this principle, Campbell J went onto explain why the Medical Appeal Panel failed in that case on the basis of insufficient reasons: "[47] […] There was no consideration of whether the physiological change by prolapse of the disc, which occurred on lifting the heavy box of pumpkins, might have occurred anyway in a healthy disc; nor is there any consideration of whether the resulting prolapse was worse because of the pre-existing abnormality; nor is there any express consideration of the means by which the pre-existing abnormality in the disc as found by the Panel contributed causally to the level of impairment, as opposed to the occurrence of the injury. There is a failure to even refer to the different opinion of the parties' medical referees." (emphasis added).
13. By way of contrast to Ryder, I accept the defendant's submission that a finding of difference in outcome is implicit in the reasons given here. The Panel recognised that the 10 April 2020 incident aggravated the degenerative condition of the lumbar spine. This necessarily connotes that there would be a different degree of damage absent this incident as it worsened the pre-existing condition. Importantly, this finding of a worsening effect is an aspect of reasoning which Campbell J expressly noted was missing in the medical panel's reasons in Ryder, resulting in error (see emphasis in italics above).
14. Thirdly, the finding, that the April 2020 frank incident aggravated the condition of the lumbar spine, did not appear in a vacuum. There was an explicit comparison of the condition of the lumbar spine both before and after the April 2020 incident, as evidenced by the June 2019 CT scan prior to the incident (which was not considered by the Medical Assessor in giving the original opinion) and a June 2020 MRI (following the referral incident) upon which the conclusion of aggravation was based.
15. Without attempting to discern the medical meaning of the findings of investigations, a matter peculiarly for medical expertise, the reasoning adopted by the Panel clearly indicates that, due to certain conditions being found and/or exacerbated in the post-referral injury investigations which were absent or less serious in pre-referral injury investigations, the 10 April 2020 incident changed the condition of the lumbar spine. The Panel stated: "26. The respondent worker suffered an injury to her back in 2019. She was referred for a CT scan of the lumbar spine on 20 June 2019. This investigation was not referred to by the MA. This investigation records a clinical history of "lumbar radicular pain on the right". The findings are reported as follows: "Mainly facet arthropathy noted, worse at L4-5 but also affects L3-4 and L5-S1. There is also moderate broad based disc protrusion at L4-5, but no canal foraminal [(sic] narrowing or nerve impingement is seen. There is sacroiliac joint arthropathy, worse on the left with cystic change." 27. What this means is that the respondent worker had chronic underlying degenerative changes in her lumbar spine which were aggravated by the injury in 2019 (not the subject of the referral). 28. After the fall on the 10 April 2020, the respondent worker was referred for a MRI investigation which took place on 18 June 2020 and was reported 19 June 2020. The clinical history is recorded as "pain radiating to under right side of heel". The findings are recorded as follows: "No fracture. No focal disc herniation. Localised advanced spondylitic changes at L4/5 level with significant degeneration and vacuum phenomenon. The disc bulge is abutting the origin of the L5 nerves in the lateral recess without compression. Severe erosive arthropathy in the L4/5 and L5/S1 facet joints worse on the right side." 29. What this means is that the respondent worker had chronic underlying degenerative changes in her lumbar spine which were aggravated by the injury in 2019 (not the subject of the referral) and again on 10 April 2020 (the subject of the referral)."
16. The relevance of the Panel itself having engaged in comparison of these investigations is it provides a stated evidential basis to support a conclusion of aggravation. The opinion of significant aggravation cannot therefore be characterised as being "devoid of support in the material": Foxtel Management at [45].
17. Finally, the Panel noted that, based upon the radiological investigations of 2019 viewed in combination with the post-referral injury investigations, the ultimate contributor to arthropathy in the L4/5 and LS/S1 facet joints was the degenerative condition: 35. The CT investigation of 20 June 2019 demonstrates facet arthropathy and disc protrusion at L4/5. 36. The MRI investigation of June 2020 demonstrates severe erosive arthropathy in the L4/54 and L5/5S1 facet joints worse on the right side." 37. The severe erosive arthropathy demonstrated in the L4/5 and LS/S1 facet joints does not result from injury on 10 April 2020 but is a pre-existing condition which was aggravated by the injury.
18. In so acknowledging that the causal source of the damage to the lumbar spine was ultimately the degenerative condition, this again provides a logical basis to conclude that merely deducting for one-tenth cannot be reconciled with the medical evidence.

Ground 3: Committing a jurisdictional error by forming an opinion [27]-[30] as part of the formation of the opinion as to whole person impairment and correcting error, by concluding that the plaintiff suffered aggravations from 2 unreferred injuries being opinions as to liability which was beyond the jurisdiction of the Medical Appeal Panel.

The Plaintiff

1. The plaintiff submitted that jurisdictional error arose from the Panel's twofold finding that: 1. The plaintiff suffered from two other injuries (or, more aptly, one degenerative condition and acute injury) which were distinct from the injury which was the subject of the referral (the 10 April 2020 injury), namely, "chronic underlying degenerative changes" to her spine, and an "injury to her back in 2019", and; 2. The effect of each of the three injuries (the degenerative changes; the 2019 incident; and the referral injury), was that each contributed to, and sequentially aggravated the impairment to the lumbar spine.
2. Making these findings, it was contended, involved the Panel erroneously engaging in an assessment of "causation" or "liability" by asking what incidents and/or conditions were responsible for the deterioration of the lumbar spine.
3. The error, as contended by the plaintiff, was that asking questions of liability exceeded the scope of the Panel's inquiry, which was confined to making a deduction. The plaintiff based this submission on the premise that the Commission is the sole repository for determining liability, or questions as to whether the workplace incident was the cause of the injury to the spine, or whether the spinal injury arose out of something entirely different. The plaintiff relied upon Jaffarie v Quality Castings Pty Ltd [2018] NSWCA 88 ("Jaffarie") to support this submission.
4. In other words, a causal connection between the 10 April 2020 incident and the impairment of the lumbar spine was already concluded and engaging in any line of questioning which may jeopardise such a conclusion was beyond the scope of the Medical Assessor's, and by extension, the Panel's, task.

The First Defendant

1. The first defendant submitted that the Panel did not exceed its jurisdiction in considering the aggravating effect of the non-referred injuries.
2. First, evidence of the degenerative condition and the 2019 injury appeared in the briefs before both the Medical Assessor and the Panel. They both had the advantage of making their respective decisions on the same material. They were, therefore, part of the dispute, the scope of which is "crystalised in documents attached to [the application to resolve a dispute] which was referred for assessment in accordance with the statute": citing Leeming JA in Skates v Hills Industries Ltd [2021] NSWCA 142 at [49]. Those respective medical facts could, therefore, be taken into account in the decision making process.
3. Secondly, and more significantly, the first defendant put that the Panel only undertook enquiries which were both relevant and necessary to the task of, firstly, assessing whether the Medical Assessor failed to correctly deduct for pre-existing injuries in accordance with s 323 of the 1998 Act, and, secondly, upon making such a finding of error, consider the process of deduction afresh. This was based upon the following reasoning: 1. The Panel did not interfere with the findings of the assessor with respect to the extent of 17% whole person impairment (12% lumbar spine; 4% left lower extremity; 1% scarring). 2. The only question that was considered by the Panel was whether the deduction of one-tenth under s 323(2) was appropriate (which is the default where the Medical Assessor considers making a precise deduction is too difficult or costly to ascertain), when considering what proportion of this 17% of damage ought to be attributed to pre-existing injuries and/or conditions based upon the medical evidence. It found the deduction of one-tenth, in relation to the 12% of whole person impairment referable to the lumbar spine, was "at odds" with the evidence. 3. Accordingly, to reissue the Certificate the Panel needed to consider the question of the appropriate deduction for the purpose of s 323 of the 1998 Act. This necessarily involved considering whether the damage to the lumbar spine was a result of, or caused by, any other injury or condition suffered by the plaintiff, and if so to what extent. Asking this question was not an impermissible consideration of issues of 'liability', in usurpation of the powers of the Commission.

Consideration Ground 3

1. Although a submission was made on behalf of the defendant, which sought to assert that the 2019 incident and the degenerative condition were permissible considerations for both the Medical Assessor and the Panel in making their respective assessments, I do not consider that this point was ever really contested.
2. Plainly, that evidence was in the brief before both the Medical Assessor and the Panel, and therefore fell within the scope of the dispute: Skates v Hills Industries Ltd [2021] NSWCA 142 at [49]. For the plaintiff to assert that evidence must not be considered, would be to contradict her own submissions, which conceded those pre-existing injuries/conditions could be taken into account for the purpose of a s 323 deduction.
3. Further, it is not in dispute that the Panel did, in fact, consider the causal relationship between non-referred injuries and the impairment to the lumbar spine. Such is clear, for example, from the Panel's finding that the ultimate cause of spinal injury was a degenerative condition, which was aggravated by the 2019 incident.
4. What was effectively in dispute is whether, in so considering this causal nexus between the impairment of the lumbar spine and the non-referred 2019 incident and the degenerative condition, the Panel exceeded the jurisdiction granted to it under Pt 7 Ch 7 of the 1998 Act. In submissions propounded by the plaintiff, the making of such findings ought to have been left to the Commission, the proper repository of power for issues of "liability".
5. To determine the merits of this submission, it is necessary to assess the delineation of power as between the Personal Injury Commission and Medical Assessors (and, by default, the Medical Appeal Panel that reviews and, where necessary, reissues the Medical Assessors decision: s 328(5)) of the 1998 Act within the statutory framework of workers compensation laws, as derived from both the 1987 and 1998 Acts. This task must be undertaken with the intention of construing when, if ever, issues of causation or liability may be considered by a Medical Assessor (and, therefore, the Panel in reviewing that decision) in the proper exercise of its powers.
6. Significantly, the Court of Appeal has already undertaken a task of this kind on several occasions: see Zanardo & Rodriguez Sales & Services Pty Ltd v Tolevski [2013] NSWCA 449 at [35]; Bindah v Carter Holt Harvey Woodproducts Australia Pty Ltd [2014] NSWCA 264 at [109]-[111]; and, Jaffarie.
7. An apt statement for present purposes is the judgment of White JA (with Macfarlan and Leeming JJA agreeing) in Jaffarie, who cited with approval a summary of a principle given by Deputy President Roche of the Workers Compensation Commission: at [80] "[80] Deputy President Roche in his judgment […] analysed in detail the reasons of this Court in Bindah and concluded as follows: "[249] Notwithstanding the different approach by Emmett JA and Meagher JA, it is my view that the following principles apply to proceedings in the Commission: (a) questions of causation are not foreign to medical disputes within the meaning of that term when used in the 1998 Act. Assessing the degree of permanent impairment 'as a result of an injury', and whether any proportion of permanent impairment is 'due' to any previous injury or pre-existing condition or abnormality, both call for a determination of a causal connection; (b) it is for the Commission to determine whether a worker has received an injury within the meaning of s 4 of the 1987 Act and whether there are any disentitling provisions, such that compensation is not payable for that injury; (c) the Commission's jurisdiction is restricted by s 65(3) of the 1987 Act, which precludes the Commission (an Arbitrator or a Presidential member) from awarding permanent impairment compensation if there is a dispute about the degree of permanent impairment, unless the degree of impairment has been assessed by an AMS; (d) the determination of the degree of permanent impairment that results from an injury is a matter wholly within the jurisdiction of the AMS or, on appeal, the Appeal Panel and is not a matter for determination by an Arbitrator; (e) a finding made by a person without jurisdiction cannot bind a person or persons who have jurisdiction, and (f) it is desirable to avoid drawing a rigid distinction between jurisdiction to decide issues of liability and jurisdiction to decide medical issues.
8. In my view, the judgment of White JA is clear authority to the effect that the plaintiff's submission fails to appreciate the true delineation of power between the Commission and the Medical Assessor/Panel.
9. In order to assess what degree of impairment to the lumbar spine is solely attributable to the referral injury, this necessarily involves considering whether any other proportion of the damage is referrable to, or caused by, some other incident, injury or condition. It follows that addressing issues of causation is a necessary incident of making deductions pursuant to s 323 of the 1998 Act. Hence, to assert that the Medical Assessor and Panel are prohibited from making these conclusions, being ones of factual causation pertaining to medical issues, would be incompatible with a substantive task the 1998 Act compels them to perform.
10. The real issues of liability which the Panel is prohibited from taking into account are those concerning whether or not the employer should be liable to compensate the worker for a workplace incident. This involves assessments which involve factual and legal questions not based upon medical expertise. For example, whether or not the worker was injured in circumstances "arising out of or in the course of employment" (ss 4 and 9(1) of the 1987 Act). This is not what has occurred.
11. This ground has not been made out.

CONCLUSION

1. In the circumstances, the plaintiff has not established any grounds of appeal and accordingly the Amended Summons is dismissed.

ORDERS

1. The orders of the Court are as follows: 1. The plaintiff's Amended Summons is dismissed.

Endnotes

1. Section 78 Notice, iCare, p 4.
2. Ibid.
3. NSW, State Insurance Regulatory Authority, NSW Workers Compensation Guidelines for the Evaluation of Permanent Impairment, (March, 2021) at 3-4 (the Guidelines) ("Guidelines for Permanent Impairment"). 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: 15 December 2023