Vos Construction & Joinery Pty Ltd v Norton-Smith

[2016] TASSC 38

[2016] TASSC 38

COURT:  SUPREME COURT OF TASMANIA

CITATION:                 Vos Construction & Joinery Pty Ltd v Norton-Smith [2016] TASSC 38

PARTIES:  VOS CONSTRUCTION & JOINERY PTY LTD
  v
  NORTON-SMITH, Greg Anthony

FILE NO:  531/2015
JUDGMENT

APPEALED FROM:  Vos Construction & Joinery Pty Ltd v N

[2015] TASWRCT 21

DELIVERED ON:  28 July 2016
DELIVERED AT:  Launceston
HEARING DATE:  4 November 2015
JUDGMENT OF:  Pearce J

CATCHWORDS:

Workers' Compensation – Proceedings to obtain compensation – Preliminary requirements – Interim payments – Tribunal erred by not finding reasonably arguable case for employer existed.

Workers Rehabilitation and Compensation Act 1988 (Tas), s 81A.
Walker v J & A Freeman Building Services [2006] TASSC 90, 16 Tas R 87; St Helens Oysters Pty Ltd v Coatsworth [2007] TASSC 90, 17 Tas R 43, applied.
Military Rehabilitation and Compensation Commission v May [2016] HCA 19, considered.
Aust Dig Workers' Compensation [303]

REPRESENTATION:

Counsel:
             Appellant:  T J Ellis SC
             Respondent:  C J Bartlett
Solicitors:
             Appellant:  C N Dockray
             Respondent:  Bartletts

Judgment Number:  [2016] TASSC 38
Number of paragraphs:  75

Serial No 38/2016

File No 531/2015

VOS CONSTRUCTION & JOINERY PTY LTD
v GREG ANTHONY NORTON-SMITH

REASONS FOR JUDGMENT  PEARCE J

28 July 2016

1. This is an appeal against a decision of the Workers Compensation and Rehabilitation Tribunal (the Tribunal), constituted by Commissioner Chandler. The appellant, Vos Construction & Joinery Pty Ltd, is a construction company. The respondent, Gregory Norton-Smith, has been employed by the appellant since October 2009. On 2 October 2014 he was a workshop co-ordinator. In these reasons I will refer to the appellant as the employer and the respondent as the worker. On 18 March 2015 the worker made a claim for compensation under the Workers Rehabilitation and Compensation Act 1988 (the Act), alleging an injury to his right knee. The employer disputed liability to pay compensation by way of weekly payments and benefits under the Act and referred the claim to the Tribunal: s 81A. On 14 May 2015 the Tribunal ordered, pursuant to s 81A(3)(a) and (b), that weekly payments and benefits should be paid to the worker: Vos Construction & Joinery Pty Ltd v N [2015] TASWRCT 21. For reasons I will expand upon later, the Tribunal must have been satisfied that there was no reasonable prospect that the claim for compensation would be rejected following a final hearing. In this appeal, the employer contends that the learned Commissioner was wrong to make that determination and those orders.

The legislation

1. The issue for determination in this appeal requires consideration of s 81A of the Act. Section 81A is part of the statutory scheme for the payment of weekly payments of compensation created by Pt VII. Where an employer has received a claim for compensation, the employer is required to commence making weekly payments: s 81(1). The purpose of the provision is to ensure that a worker who is entitled to weekly compensation should not be kept out of his or her payments while the employer decides whether to admit liability or allow the question to be decided by the Tribunal: Walker v J & A Freeman Building Services [2006] TASSC 90, 16 Tas R 87 at [20]. If an employer does not dispute liability to pay compensation under s 81A, the employer is taken to have accepted liability for the claim: s 81AB. If an employer has accepted, or is taken under s 81AB to have accepted, liability to pay compensation, or the Tribunal or a court determines that compensation is payable, the employer is also liable to pay for medical and other services necessarily incurred by the worker, referred to as "benefits": s 75. An employer who claims to have no obligation to pay compensation and benefits, and wishes to dispute liability to make them, may obtain relief from the obligation imposed by s 81 through referral to the Tribunal under s 81A. On a referral under s 81A, the Tribunal is to determine whether a "reasonably arguable case exists concerning the liability of the employer to pay weekly payments or benefits". If the Tribunal determines that a "reasonably arguable case exists" it must determine that compensation not be paid: s 81A(3)(c) and (d). If the Tribunal considers that compensation should be paid, in the form of weekly payments or benefits, then it must so order: s 81A(3)(a) and (b). Section 81A is entitled "Disputes of liability for weekly payments and other benefits" and, in full, provides:

   "(1)     An employer who disputes liability to pay compensation by way of weekly payments for an injury referred to in section 81(1) or benefits under Division 2 of Part VI must, within 84 days of receiving the claim for compensation in respect of the injury to the worker —

   (a)serve the worker with written notice that the employer disputes liability —

   (i)to pay compensation by way of weekly payments; or

   (ii)to pay any benefits payable under Division 2 of Part VI in respect of the injury; and

   (b)inform the worker of the reasons for disputing liability; and

   (c)refer the matter to the Tribunal.

   (2)     The referral of a matter to the Tribunal is to be accompanied by —

   (a)the prescribed fee; and

   (b)all evidentiary material on which the employer intends to rely at the hearing of the matter.

   (2AA) If an employer fails to lodge evidentiary material under subsection (2)(b), the employer may not rely on that material unless the Tribunal otherwise allows.

   (2A)   Where a matter is referred to the Tribunal under subsection (1), the Tribunal may authorise the Registrar to determine whether a reasonably arguable case exists concerning the liability of the employer to pay —

   (a)compensation by way of weekly payments; or

   (b)the cost of any benefits payable under Division 2 of Part VI in respect of the injury to the worker.

   (2B)  The Registrar is to advise the Tribunal of the Registrar's determination.

   (2C)  The Tribunal may make an order giving effect to the Registrar's determination.

   (3)     The Tribunal must —

   (a)if the Tribunal considers that weekly payments should be made, order the employer to make weekly payments from such date as the Tribunal determines; or

   (b)if the Tribunal considers that the cost of any benefits payable under Division 2 of Part VI in respect of the injury to the worker should be paid, order the employer to pay the cost of the benefits from such date as the Tribunal determines; or

   (c)if the Tribunal considers that a reasonably arguable case exists concerning the liability of the employer to pay compensation by way of weekly payments, determine that compensation is not to be paid by the employer; or

   (d)if the Tribunal considers that a reasonably arguable case exists concerning the liability of the employer to pay the cost of any benefits payable under Division 2 of Part VI in respect of the injury to the worker, determine that the cost of the benefits is not to be paid by the employer.

   (4)     The fact that the Tribunal has determined under subsection (3) that weekly payments should be made, or that the cost of any benefits payable under Division 2 of Part VI in respect of the injury to the worker should be paid, is not to be taken into account by the Tribunal in any other proceedings under this Act.

   (5)     Notwithstanding that liability has not been disputed in accordance with subsection (1), an employer who wishes to dispute liability to continue to pay compensation by way of weekly payments for an injury referred to in section 81(1) or to pay the cost of any benefits payable under Division 2 of Part VI in respect of the injury may, at any time after the expiration of the period referred to in subsection (1), refer the matter to the Tribunal.

   (6)     For the purposes of this section, the Tribunal or the Registrar may conduct any hearing the Tribunal or the Registrar considers necessary by any appropriate means including, but not limited to, a telephone conference."

2. The purpose and operation of s 81A was explained by Crawford J (as he then was) in Walker v J & A Freeman Building Services at [22]-[23]:

   "It obliges the employer, within a time limit, to refer the matter to the Tribunal and to establish that it has a reasonably arguable case. Indeed, it is a condition precedent, a prima facie absolute obligation, which must be fulfilled before an employer is entitled to dispute liability to commence making weekly payments following receipt of a claim. Precise Timbers Pty Ltd v Burgess at 134 and 137. However, under s81A(5), which was added to the Act after Precise Timbers Pty Ltd v Burgess was decided, although the employer must make payments of weekly compensation that have been claimed in a case where the employer has not referred the matter to the Tribunal under subs(1), nevertheless the employer may at some later time, refer to the Tribunal the question of its liability to pay. Such a reference may be made under s88.

   Section 81A provides a relatively speedy process for assessing whether an employer, who wishes to dispute liability to pay weekly compensation, has a reasonably arguable case in that regard and for the making of consequential orders of an interim nature pending eventual resolution of the dispute, should it be found that the employer has or has not a reasonably arguable case. That a speedy process is intended is demonstrated by subs(2)(a), which requires the employer to lodge with the Tribunal all evidentiary material on which the employer intends to rely at the hearing, and by subs(2AA), which permits the Tribunal to authorise the Registrar to determine whether a reasonably arguable case exists concerning the liability of the employer to pay weekly compensation. If the employer has such a case, the Tribunal will determine under subs(3)(c) that weekly compensation is not to be paid by the employer. If the employer does not have such a case, the Tribunal will order under subs(3)(a) that the employer make weekly payments. In either case, the determination or order is essentially an interim one if the unsuccessful party wishes to fully contest the question of liability later."

3. What amounts to a "reasonably arguable case" was considered by Evans J in St Helens Oysters Pty Ltd v Coatsworth [2007] TASSC 90, 17 Tas R 43 at [10]. His Honour first noted that the terms of the section involve an objective assessment of the reasonableness of the employer's arguments, and require the employer to compile and deliver evidentiary material: s 81A(2)(b). His Honour concluded that "a reasonably arguable case will exist concerning the liability of an employer to pay a worker if it is reasonably arguable on the material available in relation to the claim or identified deficiencies or weaknesses in the claim that, following a contested hearing it may be rejected". He noted the preliminary nature of the determination which results in interim orders, an observation supported by the terms of s 81A(4) which provide that a tribunal determination under s 81A(3)(a) and (b) that weekly payments or benefits be paid is not to be taken into account by the Tribunal in any other proceedings under that Act. The failure to dispute liability under s 81A(1) to make interim payments does not prevent an employer from fully contesting its liability under the Act by referral to the Tribunal: s 81A(5). Consequently, an interim determination made under s 81A does not bind the Tribunal in future proceedings to the same result, for example on the hearing of a reference under s 42, which may be determined following a fully contested hearing and on the basis of very different evidentiary material.

4. It is not enough, in a s 81A referral, for the employer to indicate that it simply wishes to put the worker to proof. The terms and history of s 81A disclose a legislative intention that an employer must do more than rely on the contention that the worker may not ultimately be unable to discharge the onus of proof. Because s 81A(2)(b) requires an employer's referral to be accompanied by all of the evidentiary material on which the employer intends to rely at the hearing, the employer bears an onus of proof of establishing a reasonably arguable case: Skilled Group Limited v Anning [2015] TASSC 18; GIO Australia Limited v Lovell [2000] TASSC 75 at [13]; Lamont v MRD Supermarkets Pty Ltd [2016] TASSC 16. The Act does not require that the employer's case about liability be strong or compelling, but the case that the claim may ultimately be rejected must be reasonably arguable. The use of those words in the legislation means that the answer to the question posed by s 81A will be a matter for assessment and judgment of the Tribunal, determined objectively, on the evidence before it in each case.

Tribunal proceedings under s 81A and appeals

1. Section 49 deals with the procedure of the Tribunal. It applies to all proceedings before the Tribunal, not just a referral under s 81A. In a proceeding before the Tribunal, the Tribunal is not bound by the rules of evidence but may inform itself on any matter in such manner as it thinks fit: s 49(1)(a). Proceedings shall be conducted with as little formality and technicality, and with as much expedition, as the requirements of the Act and proper consideration of the matters to be resolved permit: s 49(1)(b). The Tribunal is to act on such evidence as is placed before it after all of the parties have been given a reasonable opportunity to be heard: s 57(1).

2. Section 81A(6) includes an additional provision of a procedural nature which, for the purpose of the section, enables the Tribunal or the Registrar to conduct any hearing the Tribunal or the Registrar considers necessary by any appropriate means including, but not limited to, a telephone conference. That provision demonstrates an intention that the Tribunal may exercise a high degree of procedural flexibility in the resolution of an employer's reference under s 81A.

3. Section 63 provides for a right of appeal to this Court if any party to a proceeding before the Tribunal is aggrieved by a determination or order of the Tribunal, but the right is confined to appeals "in point of law". If the material before the learned Commissioner necessarily leads to a conclusion that a reasonably arguable case did exist, then he would have made an error in point of law: St Helens Oysters Pty Ltd v Coatsworth (above) at [15]; Protective Security Pty Ltd v Bedelph [2004] TASSC 128, 13 Tas R 354 per Crawford J at [22]-[28]. If, on the material before the Tribunal, reasonable minds could differ as to the existence of an arguable case, a conclusion one way or the other could not, of itself, be regarded as indicating any error of law. If the conclusion reached by the Commissioner was reasonably open, then an error in point of law has not been established: Burrage v Rural Press Limited [2013] TASSC 43.

4. There may also be an error in point of law if there is jurisdictional error.

The worker's claim and the dispute

1. The worker claimed to have suffered an injury to his right knee on 2 October 2014. Central to assessment of the claim and the issues in this appeal is the evidence that about four years earlier, in November 2010, the worker had suffered a work injury to the same knee – a medial meniscal tear which required arthroscopic surgery.

2. The disputed claim for compensation was not made until 13 March 2015, more than five months after the claimed injury, when the worker completed and signed a claim form and gave it to the employer. In the form, the worker asserts that the employer was notified of the injury at 2.30pm on 2 October 2014, an assertion not disputed by the employer. The claim was made in the approved form: s 34(1)(a). The form provides for details to be given of the worker and the injury. Under the heading "Incident & Worker's Injury Details", the worker wrote that the injury occurred on 2 October 2014 at 10.30am, when he was "walking on uneven ground, stepped on rock with right foot, pain suffered in right knee" on "levy walkway, Inveresk". In answer to the question, "What was the most serious type of injury or disease caused by this occurrence?" the worker wrote "Sprain/right knee". In answer to the question, "Is your injury or condition solely due to this occurrence?" the worker answered, "Yes".

3. The claim form was supported by a worker's compensation medical certificate completed by the worker's general practitioner, Dr Anoop Raman. The certificate is dated 10 November 2014, about five weeks after the date of the claimed injury. Dr Raman certified that he examined the worker on 10 November 2014. However, the certificate makes no reference to an injury or event on 2 October 2014. Dr Raman described the presenting symptoms as "? Meniscal injury on right knee"; his diagnosis as "Provisional"; and, as details, "Knee pain – right side". Under the section entitled, "Stated cause", Dr Raman certified that the worker stated the condition to be caused by "An incident which occurred on November/2010", and that the injury or disease occurred in the following circumstances: "Happened at work in 2010. Treated with arthroscopy in 2011. OK for a while. Now symptoms came back again." In answer to the question, "If known, the injury or disease is:", Dr Raman wrote, "A recurrence of a previous compensable condition." The form of certificate seeks details of past history of similar injury, to which Dr Raman responded "Initial injury happened in 2010." Dr Raman did not certify the worker as wholly incapacitated for work. He certified that the worker would be "fit for suitable duties" and that he should "avoid repetitive bending and heavy lifting. Work as pain permits. May take rest if needed."

4. By letter dated 16 April 2015, the employer's insurer wrote to the worker giving notice under s 81A(1)(a) of the employer's dispute of liability to pay compensation. The letter gave the following reason:

   "1   You have not suffered an injury which has arisen out of or in the course of your employment with the employer and to which your employment contributed to a substantial degree, as required by section 25(1)(a) or (b) of the Act on 2 October 2014 as alleged in your injured worker's details report dated 13 March 2015.

   The employer says that the alleged injury suffered on 2 October 2014 is not supported by the initial workers compensation medical certificate of Dr Anoop Raman dated 10 November 2014, nor is it supported by Professor B J Einoder, the worker's treating orthopaedic surgeon, in his report of 24 November 2014."

5. The employer's referral to the Tribunal under s 81A identifies the reason for the dispute in identical terms. The referral was accompanied by other evidentiary material produced by the employer to which I will refer shortly.

The right to compensation under the Act

1. The issue raised by the employer's notice and referral was whether the worker suffered an injury on 2 October 2014 and the contribution of employment to any injury. Thus, the issue for the Tribunal on the s 81A referral became, on the evidence before it, whether it was reasonably arguable that the worker did not suffer a compensable injury on that day. In this appeal, consideration of that issue requires analysis of the statutory basis of an employer's liability for compensation payable under the Act. An employer's liability to pay compensation derives from s 25(1) and arises when, "in any employment:

   (a)a worker suffers an injury, not being a disease, arising out of or in the course of his employment; or

   (b)a worker suffers an injury, which is a disease and to which his employment contributed to a substantial degree, within the meaning of section 3(2A)".

2. The term "injury" is defined in s 3 which, so far as it is relevant to this appeal, reads:

   "injury includes —

   (a)a disease; and

   (b)the recurrence, aggravation, acceleration, exacerbation or deterioration of any pre-existing injury or disease where the employment was the major or most significant contributing factor to that recurrence, aggravation, acceleration, exacerbation or deterioration."

1. The term "disease" is also defined in s 3 to mean:

   "any ailment, disorder, defect, or morbid condition, whether of sudden or gradual development."

2. By s 3(2A), employment contributed to a disease to a substantial degree only if it is the major or most significant factor.

3. There are some observations which may immediately be made about these and associated provisions:

   ·     there can be no liability unless a worker has suffered an injury;

   ·     there are two categories of injury: an injury (not a disease) and an injury which is a disease;

   ·     the statutory definition of injury is inclusive. It extends, but does not attribute a meaning to, the term injury when used in its primary sense;

   ·     if an injury is not a disease, there is no liability unless the injury arises out of or in the course of the worker's employment. The words of connection to employment are disjunctive – it must have a causal or temporal connection with the worker's employment;

   ·     if the injury is a disease, there is no liability unless the worker's employment contributed to it to a substantial degree. By s 3(2A), employment contributed to a disease to a substantial degree only if it is the major or most significant factor;

   ·     a recurrence, aggravation, acceleration, exacerbation or deterioration of any pre-existing injury or disease is an injury, but only where the employment was the major or most significant contributing factor to that recurrence, aggravation, acceleration, exacerbation or deterioration.

4. In considering whether there is an injury which is a disease, the tribunal of fact is to consider whether the evidence establishes what may properly be described as an "ailment, disorder, defect, or morbid condition". If so, the tribunal of fact must then consider whether the worker's employment is the major or most significant factor contributing to the disease. If the evidence establishes both questions in the affirmative, then the condition is an injury.

5. If there is no injury (which is a disease), then consideration is to be given to whether there has been an injury in the primary sense. Although the Act does not define the meaning of the term "injury" in that sense, its meaning has recently been considered by the High Court in Military Rehabilitation and Compensation Commission v May [2016] HCA 19. At [52] the majority pointed out that whether there is such an injury will generally be determined by asking whether a worker has suffered something that can be described as a sudden and ascertainable or dramatic physiological change or disturbance of the normal physiological state. The majority applied the reasoning of Gleeson CJ and Kirby J in Kennedy Cleaning Services Pty Ltd v Petkoska [2000] HCA 45, 200 CLR 286. Both cases considered legislation which is comparable, though not identical, to the Tasmanian legislation. In Kennedy Cleaning v Petkoska, at 300 [39], Gleeson CJ and Kirby J explained:

   "[C]onsideration [must] be given to the precise evidence, on a fact by fact basis, concerning the nature and incidents of the physiological change accepted at trial. If this evidence amounts, relevantly, to something that can be described as a sudden and ascertainable or dramatic physiological change or disturbance of the normal physiological state, it may qualify for characterisation as an 'injury' in the primary sense of that word."

6. See also the passages in their Honours' reasons in Kennedy Cleaning Services Pty Ltd at 298-299 [35] and 300-301 [40]. Their Honours earlier explained at 296 [28] that because of the disjunctive formulation in the phrase "out of or in the course of employment" many injuries "are compensable simply because they have occurred during the protected period of work hours, although they have no other connection with the worker's employment". They continued at 300 [39] by pointing out that if a physiological change in the sense described "happens within the protected period of employment, it is ordinarily compensable without proof of a specific causal connection with the workers' employment".

7. There is no dichotomy between an injury which is a disease and an injury which is not a disease. A worker is entitled to recover if he or she falls within either head of recovery: Zickar v MGH Plastic Industries Pty Ltd (1996) 187 CLR 310 per Kirby J at 351, applied by McHugh, Gummow and Hayne JJ in Kennedy Cleaning v Petkoska at 310 [73].

8. In the event that the evidence does not establish an injury which is a disease or an injury in the primary sense, it may then be necessary to ask whether the case is one involving a recurrence, aggravation, acceleration, exacerbation or deterioration of a pre-existing injury or disease within the operation of par (b) of the s 3 definition. The concept of a par (b) injury was considered in detail by Porter J in Long v Kmart Australia Ltd [2016] TASSC 6. That case concerned a pre-existing disease, and not a pre-existing injury, but many of his Honour's observations, and the authorities he referred to, are applicable to both. In Tasmania, the terms "recurrence, aggravation, acceleration, exacerbation or deterioration of a pre-existing injury or disease" were introduced into par (b) of the definition of "injury" by amendment in 2001. The terms are commonly used in workers' compensation legislation in Australia. Judicial consideration of the terms is more commonly by reference to pre-existing disease rather than pre-existing injury. The terms recurrence, aggravation, acceleration, exacerbation and deterioration, when applied to a pre-existing injury, mean something which results in an increase or intensification of symptoms: Federal Broom Co Pty Limited v Semlitch [1964] HCA 34; 110 CLR 626 per Kitto J at 634 where his Honour considered what amounted to exacerbation of a disease. A recurrence, aggravation or exacerbation may arise as a result of external stimuli, or as a result of natural progression of the condition or symptoms: Cook v Midpart Pty Ltd [2008] NSWCA 151, 6 DDCR 316 at [41]-[49].

9. Because of the meaning of injury to which I have referred, the terms recurrence, aggravation, acceleration, exacerbation and deterioration, when applied to a pre-existing injury, could only refer to some circumstance causing an increase or intensification of symptoms, but not amounting to the type of physiological change which itself amounts to injury in the primary sense. If something amounts to an injury in the primary sense, then resort to par (b) of the extended definition is unnecessary. In these reasons I may, on occasion, refer to the five terms used in the definition by the shorthand term "recurrence" or "aggravation", although the words used in par (b) are not synonymous, have different shades of meaning and are not mutually exclusive: Federal Broom Co Pty Limited v Semlitch per Kitto J at 634; Long v Kmart Australia Ltd at [47]. If the evidence establishes a recurrence, it does not give rise to a liability to pay compensation unless the worker's employment is the major or most significant contributing factor to the recurrence. In that case, it must be possible to identify some incident or state of affairs to which the worker was exposed in the performance of his employment which was the major or most significant contributing factor to the recurrence: Federal Broom Co Pty Limited v Semlitch per Kitto J at 632.

10. By extension of the pre-existing disease authorities, the result of the combined operation of par (b) of the definition of "injury" in ss 3 and 25(1)(a), is that if a worker is suffering from a pre-existing injury, however contracted, and if the employment contributed to an aggravation or recurrence to the requisite degree, then there is an injury within the meaning of the Act: Amalgamated Wireless (A/Asia) Ltd v Philpott (1962) 110 CLR 617 at 625; Darling Island Stevedoring and Lighterage Co Ltd v Hankinson (1967) 117 CLR 19 at 26. It is the contribution of the employment to the recurrence of the pre-existing injury which is to be assessed, not the effect of the original injury. In an appropriate case, the contribution of the natural progression of effects of the pre-existing injury is to be taken into account: Cook v Midpart Pty Ltd at [39]-[49], applied in Long v Kmart Australia Ltd at [67].

The evidence before the Tribunal

1. The Commissioner's written reasons for decision disclose the evidentiary material which was before the Tribunal. Most, but not all, of the material was produced by the employer. It either accompanied the reference as required by s 81A(2)(b), or was produced to the Commissioner at the hearing. It comprised:

   ·     the claim form;

   ·     Dr Raman's medical certificate;

   ·     reports of Mr Roger Butorac dated 12 February 2007 and 22 March 2011;

   ·     a report from Professor B J Einoder dated 24 November 2014; and

   ·     a report from Dr David Ruttenberg dated 20 February 2015.

2. The worker appeared before the Tribunal unrepresented. He did not give evidence in the formal sense, or produce any material, but during the hearing he said something about what had happened to him. The Tribunal's reasons record that "from the bar table the worker confirmed that he had injured his right knee at work in 2010 but had been symptom free following the surgery. This continued up to October 2014 when symptoms returned following the incident at Inveresk when he stepped on a rock".

3. I have already referred to the contents of the claim form and the certificate. The report from Mr Roger Butorac dated 12 February 2007 refers to an injury to the worker's left knee. It is irrelevant. However Mr Butorac's report of 22 March 2011 describes the earlier injury to the worker's right knee suffered by him when working for the same employer in November 2010. The report describes Mr Butorac's treatment of the worker following a consultation on 8 February 2011. The report reads, in part:

   "Mr Norton-Smith is a 38 year old man who informed me that he had been troubled by pain and swelling in his right knee. The symptoms apparently first developed whilst he was at work in November 2010. He had been lifting some heavy fence panels and concrete blocks onto a trailer for transport when his knee became painful. Later he noticed that it was swollen … The symptoms and clinical findings were consistent with a medial meniscal tear and I suggested arthroscopic intervention."

   Mr Butorac opined that "the most likely diagnosis here is one of a medial meniscal tear on the right knee".

4. There is no report from Mr Butorac following performance of the arthroscopic surgery which he recommended. Professor Einoder is an orthopaedic surgeon. His report dated 24 November 2014 confirms that surgery recommended by Mr Butorac took place on 27 May 2011. Professor Einoder's report was obtained by the employer's insurer. I infer from the date of the report that it was sought in response to the worker's initial notice of injury. In the report Professor Einoder states that he saw the worker on 19 November 2014 at the request of Dr Raman. The report includes the following passages:

   "Greg advised me that in the preceding months he had done some unaccustomed excessive walking on uneven ground and developed pain in his right knee joint. This gradually became associated with swelling and caused him to limp. Despite his symptoms he tried to continue with his normal duties …

   Greg advised me that in November 2010 after some unaccustomed excessively heavy work he developed similar symptoms. He failed to improve with conservative treatment, hence on the 27^th May 2011 Mr Butorac perform an arthroscopic partial meniscectomy. Post operatively he gradually improved and had been asymptomatic until one month ago …

   As I see it this man's symptoms and signs are consistent with a medial meniscus derangement associated with some adjacent articular cartilage damage of the medial femoral and tibial condyles …

   The femoral condyle is spherical in shape and the tibial condyle is flat and hence to make one surface conform with the other you need a wedge shaped meniscus. Having a portion of this meniscus removed significantly changes the biomechanics of the knee joint and makes it more susceptible to further injury to the articular cartilage. In the absence of any other significant incident I expect that Mr Norton-Smith's current problem can still be related to the initial problem he had on the 26^th November 2010. Although he has no significant radiological changes at this time I would expect an MRI to demonstrate that he does have articular cartilage damage to the medial compartment and a further derangement of his medial meniscus. Since his diagnosis is quite obvious I have not organised for him to have an MRI."

5. Dr Ruttenberg is a consultant occupational physician. He assessed the worker on 13 February 2015 at the request of the employer's insurer. His report is dated 20 February 2015. It did not accompany the employer's reference to the Tribunal. Some implied criticism of the employer was made of this by counsel for the worker during the hearing of the appeal. I do not see any proper basis for the criticism. It could only be relevant to determining whether the Tribunal's findings and conclusion were open to it as a matter of law. The Commissioner said nothing to indicate that he drew any inference adverse to the employer from how the report came to be produced, and no such inference was warranted. The Act requires only that the reference be accompanied by the evidentiary material on which an employer intends to rely. When it emerged in the course of the hearing that the report existed, the employer agreed to produce it. Dr Ruttenberg's report describes the worker having given a history in the following terms:

   "Mr Norton-Smith, a 42 year old gentleman, presents with a history of right knee symptoms first noted on 10 November 2014, and while in his working environment. He tells me that he was loading his truck and walking alongside. The ground was uneven and he tread [sic] on a rock. He tells me that the right knee joint was displaced medially. There was sudden pain and swelling over the medial aspect of the knee joint."

   A little later in the report, in referring to the medical history he had been given by the worker, Dr Ruttenberg said:

   "He confirms injury in 2010 with arthroscopy in 2011. He was unable to work over a week but made a full recovery 'no problems'."

6. Dr Ruttenberg was asked to give his diagnosis. He said:

   "The diagnosis is of right medial meniscal pathology. This is in the context of what may well be degenerative change affecting the medial compartment of the right knee joint."

7. He was given the definition of "disease" in the Act and asked for his opinion whether the worker's claim was "for a disease", and, if so, whether his employment was the major or most significant cause. He wrote:

   "It is my opinion given the history elicited today, that it is quite plausible that he suffered an acute event an injury and that there was force associated with the knee joint moving sideways and prior to symptom onset. In this regard, his symptom complex would be an injury and not a disease. I note that this is slightly a variance with Professor Enidoer's letter and the workers compensation medical certificate that do not document an acute event prior to symptom onset. If the latter is the case, then he has suffered a disease. The history elicited today suggests that this is an injury. …

   It follows that his employment was the major most significant factor if indeed there was sudden force and he developed an acute onchronic condition and a tear of the right medial meniscus."

8. Dr Ruttenberg was asked about underlying factors contributing to the worker's condition and incapacity and wrote:

   "There are other contributing and underlying factors and I note that he does have degeneration already affecting the medial meniscus and the medial compartment of the knee. The latter is plausibly secondary to the arthroscipient surgery, noting that a meniscectomy procedure will predispose to the development of medical compartment arthritic change.

   An MRI scan could yet be carried out to confirm the status of the medial compartment of the right knee joint in general. This would certainly assist in clarifying whether he suffered a new injury or whether indeed, the changes are all pre-existing and relate either to the previous injury or degeneration that is present…

   At this stage in the absence of an MRI scan being carried out I could not confirm that ongoing symptoms and relative incapacity relates to a pre-existing condition."

The Tribunal decision

1. In his reasons, the Commissioner analysed the details given in the worker's claim form and Dr Raman's medical certificate. He referred to the statutory definition of injury and concluded that the injury for which the worker claimed compensation was a "recurrence of his 2010 knee injury". Having reached that conclusion he stated the issue to be determined as "whether, following a contested hearing, the employer may be able to avoid liability to pay compensation for this injury on the basis that it was not causally related to the worker's employment to the extent required by s25(1)(a) or (b)". The Commissioner noted the absence of a report from Mr Butorac about the cause of the worker's present condition and continued:

   "Professor Einoder, however, has recently examined the worker. In the history taken by him he has not recorded a specific incident involving the worker stepping on a rock although he did note, consistent in part with the worker's account, that he had been walking on uneven ground when he experienced pain in his right knee. Most relevantly Professor Einoder has opined that the worker is suffering from a medial meniscus injury which he considers to be related to the worker's 2010 injury. Further, it is noted that Professor Einoder has not identified any factor, outside the worker's employment, which may have caused or contributed to the current status of his right knee. Overall Professor Einoder's report is consistent with the contents of Dr Raman's initial medical certificate. This brings me to Dr Ruttenberg.

   Dr Ruttenberg has also recently examined the worker. At the time he had access to all the relevant documentation. He obtained a history largely consistent with the worker's claim form save that he has recorded 10 November 2014 as the date the worker first noted his knee symptoms. The worker's claim form shows this date to be 2 October 2014. I note that 10 November was the date the worker first consulted Dr Raman and it may be that Dr Ruttenberg has confused this date with the date of the event which the worker said precipitated his symptoms. However, little turns, in my view, upon clarification of the precise date. This is so because, whatever the date, Dr Ruttenberg is in step with the opinions of Dr Raman and Professor Einoder that the worker currently suffers from a right meniscal injury. Further he does not identify any factor outside of the worker's employment which may have caused his current injury and in fact positively asserts that employment to be the major or most significant contributing factor."

2. On the basis of his review of the evidence, the Commissioner concluded that he could not be satisfied, based upon the material before the Tribunal, that the employer may be able to avoid liability for the worker's claim "on the basis that his injury is not causally related to his employment" as required by the Act. He concluded that, to his mind, the evidence compelled the opposite conclusion.

The appeal

1. Grounds 8 and 9 assert an error of law arising from the manner in which the Tribunal characterised the question to be determined on the reference. Ground 8 asserts that the error is jurisdictional error. If those grounds are made out then the manner in which the remaining grounds are to be dealt with is affected, and so I will deal with them first.

Ground 8

1. Ground 8 reads:

   "The learned Commissioner erred in law, failed to act within his jurisdiction or alternatively failed to exercise his jurisdiction and denied the Appellant natural justice when he failed to proceed from a correct and accurate understanding and recitation of the basis upon which the employer disputed the claim and sought a reasonably arguable case determination, in that the employer did not do so on the basis that the injury was not casually [sic] related to the worker's employment but did so on the basis that the worker did not suffer an injury which arose out of or in the course of his employment and to which his employment contributed to a substantial degree."

1. In the first paragraph of the Tribunal's reasons the Commissioner said:

   "The employer disputes liability for the claim and seeks a reasonably arguable case determination on the basis that the injury is not causally related to the worker's employment to the degree required by s25(1)(a) of (b) of the Act."

2. With respect, by restating the dispute in those terms, the Commissioner mischaracterised the employer's position. It was an incomplete statement of the matters disputed by the employer's notice and reference, which squarely put in issue whether the worker had suffered a compensable injury, not just the contribution of employment to injury. Nevertheless, the Tribunal determined the reference on the basis that the claimed injury was a recurrence of the 2010 injury. In his reasons, after referring specifically to the claim form and Dr Raman's certificate (and only to those two documents), the Commissioner stated:

   "This brief analysis leads me to conclude that the injury for which the worker claims compensation is a recurrence of his 2010 knee injury."

3. That statement reads as a final determination of a question of fact. The Tribunal's function was not to make final findings of fact. Rather, it was to determine whether there were reasonable arguments about the employer's liability; that is, whether it was reasonably arguable that the worker did not suffer a recurrence of a pre-existing injury. The Commissioner's earlier reference to the relevant passage from the decision of Evans J in St Helens Oysters v Coatsworth makes clear that he properly understood his function, and he was required to make his own assessment of the strength of the employer's case. That the Commissioner expressed the finding of a recurrence as he did may mean that he was not satisfied that the employer may avoid liability on the basis that there was no recurrence of the 2010 injury. But he did not say that, and he did not address any of the other evidence which was relevant to the employer's arguments about that question. At the end of the reasons, the Tribunal's conclusion was expressed in terms only that the Commissioner was not satisfied that the employer may be able to avoid liability on the basis that the worker's injury was not contributed to by employment to the requisite degree. It may be that the Commissioner incorrectly considered that the contribution of employment was the only disputed aspect of the claim. By ground 8, the employer contends that the Commissioner, by mischaracterising the issues raised by the reference and failing to consider and determine whether there was a reasonably arguable case that the worker did not suffer a recurrence, thereby made an error in point of law in the nature of jurisdictional error of the type identified by the High Court in Minister for Immigration and Multicultural Affairs v Yusuf  (2001) 206 CLR 323 at [74]:

   "What is important, however, is that identifying a wrong issue, asking a wrong question, ignoring relevant material or relying on irrelevant material in a way that affects the exercise of power is to make an error of law. Further, doing so results in the decision-maker exceeding the authority or powers given by the relevant statute. In other words, if an error of those types is made, the decision-maker did not have the authority to make the decision that was made; he or she did not have jurisdiction to make it."

4. The difficulty of distinguishing between jurisdictional and non-jurisdictional error was recognised by the High Court in Craig v South Australia (1995) 184 CLR 163 at 176–180 and in Kirk v Industrial Court (NSW) [2010] HCA 1, 239 CLR 531. It has been suggested that different principles apply to courts on the one hand and inferior tribunals on the other: Craig at 176-177 and Kirk at 572 [67]-[69]. At least part of the reason for the different approach is that a court is constituted by persons with legal training entrusted with authority to decide questions of law, contrasted with the lack of authority of an administrative tribunal, in the absence of contrary intent in the statute establishing it, to authoritatively determine questions of law, or to make a determination otherwise than in accordance with the law. Difficulties arising from the notion of what is "authoritative" were discussed in Kirk at 573 [69]-[70], and the problem of drawing a distinction between a court and an administrative tribunal is apparent in this case. The Tribunal is not a court, but it may only be constituted by commissioners who are legal practitioners of more than five years' standing: ss 17A, 17B, 18 and 19. The Tribunal's function is to determine all claims and matters referred to under the Act and to exercise all of the powers conferred and duties imposed under the Act: s 20. It has jurisdiction to perform all of those powers and duties, and proceedings for compensation may only be brought before the Tribunal: s 23(2). In those circumstances, I think that statements of the law about the principles to be applied to inferior courts should be applied in this case. Accordingly, the above passage from Yusuf concerning a decision of an administrative tribunal is to be read in light of the following. In Re Refugee Review Tribunal; Ex parte Aala [2000] HCA 57, 204 CLR 82, Hayne J said at 141 [163] - :

   "The difficulty of drawing a bright line between jurisdictional error and error in the exercise of jurisdiction should not be permitted, however, to obscure the difference that is illustrated by considering clear cases of each species of error. There is a jurisdictional error if the decision maker makes a decision outside the limits of the functions and powers conferred on him or her, or does something which he or she lacks power to do. By contrast, incorrectly deciding something which the decision maker is authorised to decide is an error within jurisdiction. (This is sometimes described as authority to go wrong, that is, to decide matters within jurisdiction incorrectly.) The former kind of error concerns departures from limits upon the exercise of power. The latter does not."

5. In Kirk, the plurality, after referring to the passage from the judgment of Hayne J just quoted, continued at 572 [67]:

   "By contrast, demonstrable error on the part of an inferior court 'entrusted with authority to identify, formulate and determine' relevant issues, relevant questions, and what is and what is not relevant evidence was held, in Craig, not ordinarily to constitute jurisdictional error. The Court held that:

   'a failure by an inferior court to take into account some matter which it was, as a matter of law, required to take into account in determining a question within jurisdiction or reliance by such a court upon some irrelevant matter upon which it was, as a matter of law, not entitled to rely in determining such a question will not ordinarily involve jurisdictional error'." [Footnotes omitted.]

6. In this case, the Tribunal did not misapprehend or disregard the nature or limits of its functions or powers. It did not operate outside the general area of its jurisdiction. It did not act in absence of a jurisdictional fact. Nor, in my view, did it disregard a matter that the Act required it to take into account as a condition of jurisdiction, or misconstrue the Act. A mischaracterisation of the issue it was required by the reference to determine, and failure to take into account material relevant to an issue it was required by the reference to determine, were not jurisdictional errors, but errors within jurisdiction, and thus not errors in point of law. Nor does any such failure constitute a breach of natural justice. The Tribunal complied with its duty to extend natural justice to the employer. This ground is not made out.

Ground 9

1. Ground 9 reads:

   "The learned Commissioner erred in law in characterising the nature of the claim as one for a recurrence of the 2010 knee injury when the declaration made by the worker made no such claim and further or in the alternative when the proper characterisation of the worker's claim was a contestable matter which ought not to have been resolved at that stage."

2. In determining the reference, the Tribunal did not consider whether a reasonably arguable case existed on any basis other than that the claim was for a recurrence of a pre-existing injury. By ground 9, the employer contends that the Tribunal thereby wrongly confined the nature and scope of the claim to a recurrence, when the worker had made no such claim. I do not agree that the Tribunal made an error of law by proceeding as it did. The worker was unrepresented at the hearing. It was for the Tribunal to identify and determine the issues raised by the reference, including the grounds on which the claim may be susceptible to reasonable argument. If the Tribunal properly determined that the employer did not have a reasonably arguable case on liability on a particular basis, then no further determination was necessary. The Tribunal did not consider whether the worker suffered an injury in the primary sense, or an injury which is a disease because, having found that it was a recurrence of a pre-existing injury, it was unnecessary that it do so. Whether it was compelled to find that the employer had a reasonably arguable case about liability on that basis is a different question and is dealt with under other grounds.

3. This ground is not made out.

The remaining grounds

1. The remaining grounds all contend in various ways that the Tribunal erred in point of law in failing to find it reasonably arguable that the worker did not suffer a compensable injury. The grounds can only succeed if the employer establishes that the evidence necessarily led to the conclusion that it had a reasonably arguable case. This is not a case in which the Tribunal enjoyed any particular advantage arising from an ability to hear and observe witnesses. The evidence before the Tribunal was almost entirely in the form of the medical reports, and no witnesses gave evidence or were cross-examined. This Court is in just as good a position to judge what inferences could and should be drawn from the evidentiary material.

2. The grounds have their genesis in what the employer contends is reasonable argument about the existence and nature of the claimed injury and how and when it occurred, arising in part from what the employer contends are differing accounts given in the claim form and medical reports. The precise accounts are set out earlier in these reasons, but the substance can be stated as follows:

   ·     in the claim form the worker said that while walking on uneven ground on 2 October 2014 he stepped on a rock, and that the injury was solely due to that occurrence;

   ·     Dr Raman's medical certificate refers to presenting symptoms of "?meniscal injury to the right knee" which the worker stated were caused by an incident at work in November 2010, that symptoms have "come back", and are consistent with recurrence of a previously compensable condition;

   ·     Professor Einoder's report records the worker telling him that in the months preceding October 2014 he had done some unaccustomed excessive walking on uneven ground and developed pain in his right knee joint, which gradually became swollen and caused him to limp;

   ·     Mr Ruttenberg reported a history of right knee symptoms first noticed by the worker on 10 November 2014 when, while loading his truck and walking alongside on uneven ground, he trod on a rock, causing sudden pain and swelling.

3. The employer highlights the contrast between Professor Einoder's description of the gradual development of pain and swelling caused by walking on uneven ground (not identified as being at work) over months, Dr Ruttenberg's report of what was described to him as a frank injury on a particular date, the report in the claim form of a frank injury on 2 October 2014 and, finally, Dr Raman's certificate of the recurrence of a previously compensable condition stated by the worker to have been caused by an incident in November 2010 without reference to any event on 2 October 2014.

4. The Tribunal did not consider whether the worker suffered an injury which is a disease, or, more correctly, whether it was reasonably arguable that the worker did not suffer an injury which is a disease. That is understandable because, in my respectful view, the Tribunal could only have concluded that a reasonably arguable case existed concerning the liability of the employer to pay compensation and benefits on the basis that the worker suffered from a disease or a recurrence of a disease, and whether the employment was the major or most significant contributing factor to a disease or recurrence of a disease.

5. Neither did the Tribunal determine whether it was reasonably arguable that an injury in the primary sense had not occurred. It did not do so presumably because the Tribunal considered it sufficient to base its determination on the finding of a "recurrence". If, on the ultimate resolution of the claim, the worker establishes that he suffered an injury in the primary sense of a sudden and ascertainable or dramatic physiological change or disturbance of the normal physiological state while at work on 2 October 2014, then that is sufficient to found a compensable claim under s 25(1)(a) without resort to either limb of the extended definition of injury. The worker's own account at the hearing supported a claim on that basis. Dr Ruttenberg's opinion, based on the history given to him by the worker of stepping on a rock, was that the worker "developed an acute onchronic condition and tear of the right medial meniscus". Dr Ruttenberg reported that the symptoms were "first noted on 10 November 2014" when the worker "tread" (sic) on a rock at work. The date referred to by Dr Ruttenberg is not the date the worker said he was injured; it is the date of Dr Raman's certificate. If it is intended to be a reference to the date of the injury, the Commissioner was entitled to conclude that it was a simple error. If the worker's account and Dr Ruttenberg's view, based on the history given to him by the worker of a discrete event and injury are accepted, then liability would exist for an injury in the primary sense, on whatever date. If an injury in that sense occurred it is not necessary that employment be the major or most significant contributing factor. However, I think that, on the material before it, the Tribunal could only have found that there was a reasonable argument about whether there had been a sudden and ascertainable or dramatic physiological change or disturbance of the normal physiological state of the worker's right knee at work on 2 October 2014. Dr Ruttenberg's opinion was primarily based on the history given to him of an acute event and injury. The argument arises from the terms of the certificate, which attributes the worker's symptoms on presentation to recurrence of symptoms arising from the 2010 injury without reference to 2014 employment, and Professor Einoder's opinion that "the current problem can still be related to the initial problem he had on the 26^th November 2010". In his report about the worker, Professor Einoder refers to "articular cartilage damage to the medial compartment and a further derangement of his medial meniscus" (my emphasis), but does not explain the nature and extent of the further derangement he referred to, or attribute it to any employment event.

Ground 1

1. Ground 1 reads:

   "The learned Commissioner erred in law in determining that the evidence adduced by the employer established an uncontestable fact that the worker's claim was for a recurrence of his 2010 injury where the employment was the major or most significant contributing factor to that recurrence such a determination giving rise to new rights and liabilities under the Act when on the evidence the determination that the worker suffered a recurrence of his November 2010 injury where the employment was the major or most significant contributing factor to that recurrence was a contestable proposition."

2. This ground raises more than one issue. Some can be dealt with quickly. The first is the reference to "new rights and liabilities". Whether the claim gave rise to new rights and liabilities is irrelevant to the determination of the question raised by this ground. Counsel for the employer also made submissions about whether different insurers may be liable, and that different compensation caps, limits and rates may be affected. To those considerations I would add that different employers may be involved. Those matters are likewise irrelevant. If the worker suffered a recurrence of a pre-existing injury to which employment was the major or most significant contributing factor, then it was a compensable injury. The matters to which I have referred follow from that result but are not determinative of it. This and other grounds refer to whether a fact is "contestable" or "uncontestable". The words are not used in the legislation. What is to be determined is whether a reasonably arguable case exists concerning the liability of the employer to pay compensation.  

3. Because, as I have explained, there could only have been a reasonable argument about every other basis for the employer's liability to pay compensation under the Act, resolution of this appeal distils to the question of whether it was reasonably open for the Tribunal to find that the employer did not have a reasonably arguable case about whether the worker suffered a recurrence of a pre-existing injury, contributed to by employment, to the requisite degree. Were the claim to be referred for a full hearing, liability for compensation is not established on this basis unless the worker establishes both a recurrence of a pre-existing injury and the contribution of employment to the recurrence to the requisite degree. Whether a reasonably arguable case exists is to be considered in light of all of the issues and competing contentions, but both elements are essential to liability.

4. Whether there is a recurrence, aggravation, acceleration, exacerbation or deterioration is a question of fact: Adelaide Stevedoring Co Ltd v Forst (1940) 64 CLR 538; Federal Broom Co Pty Limited v Semlitch per Windeyer J at 637. It is important to remember that the Tribunal was not to make final determination of whether there had been a recurrence. The Tribunal was required to consider whether the employer had a reasonably arguable case. In doing so, assessment of the strength of the competing factual contentions open on the evidence was necessary so that the Tribunal could exercise its function. There was ample evidence from which to conclude that the worker's right knee symptoms had become worse. However, I think that the evidence before the Tribunal compelled the conclusion that it was reasonably arguable that the worsening of symptoms was not a recurrence of a pre-existing injury. When concluding that the worker had suffered a recurrence, the Tribunal referred only to the claim form and Dr Raman's certificate. Other material raised other reasonable possibilities. The first and most obvious alternative is that the worker had suffered a fresh work injury in the primary sense. That was what the worker claimed. Dr Ruttenberg's primary opinion was to that effect. Of course, this would have given rise to a compensable claim in any event. As I have already explained, if it was a fresh injury in the primary sense, there was no need to resort to the concept of recurrence.

5. It may be that, although he did not say so, the Commissioner was intending to convey that the employer should not escape liability to make interim payments if, whether the claim was viewed as for an injury or a recurrence, compensation was payable. In other words, that the worker should not fall between the two scenarios if one must be true, and that taken overall, it was not reasonably arguable that the worker did not suffer either an injury in the primary sense or a recurrence of a pre-existing 2010 injury. However, there were reasonable arguments about whether there had been an injury in the primary sense and other reasonably arguable possibilities inconsistent with a recurrence. Although Professor Einoder's report indicates that surgical removal of part of the meniscus makes the knee "more susceptible to further injury of the articular cartilage", his opinion that the worker's "current problem" is related to the 2010 problem is qualified by there being an absence of "any other significant incident". There was evidence that the worker had been asymptomatic following his recovery from the surgery performed by Mr Butorac in 2011, and Mr Butorac's report of 22 March 2011 indicated that following the surgery the worker "would not be particularly predisposed to recurrence of the problem". Dr Ruttenberg diagnosed the worker as suffering right medial meniscal pathology, but "in the context of what may well be degenerative change affecting the medial compartment of the right knee joint". He described what "may be" degenerative change affecting the right knee, but he said it was "plausibly secondary to the surgery", which may also "predispose to the development of medial compartment arthritic change". The employer submits that a vulnerability or pre-disposition points to the proposition that the re-emergence of symptoms in 2014 may not be a recurrence of the 2010 injury. 

1. Whatever conclusion is reached about the fact of recurrence, the evidence compelled the conclusion that the employer had a reasonably arguable case concerning the second element essential to liability for recurrence. It must be shown that a recurrence, if established, is contributed to by the worker's employment to the requisite degree. Again, subject to my earlier comments about the Tribunal's function in a s 81A reference, it is a question of fact: Kooragang Cement Pty Ltd v Bates (1994) 35 NSWLR 452. In that case, Kirby P (as he then was) said, with the agreement of Sheller and Powell JJA, at 463:

   "The result of the cases is that each case where causation is in issue in a workers compensation claim, must be determined on its own facts. Whether death or incapacity results from a relevant work injury is a question of fact. The importation of notions of proximate cause by the use of the phrase 'results from', is not now accepted. By the same token, the mere proof that certain events occurred which predisposed a worker to subsequent injury or death, will not, of itself, be sufficient to establish that such incapacity or death 'results from' a work injury. What is required is a commonsense evaluation of the causal chain."

2. For liability to be established it must be possible to identify some incident or state of affairs to which the worker was exposed in the performance of his employment which was the major or most significant contributing factor to the recurrence. I am satisfied that there were deficiencies or weaknesses in the claim in this respect which supported a reasonable argument that the claim may not succeed. Whether there is a reasonably arguable case invites consideration of whether the material before the Tribunal discloses any other possible cause of the recurrence, such that an incident of employment may not be the major or most significant contributing factor. On that question the learned Commissioner referred to the claim form and the reports of Professor Einoder and Dr Ruttenberg, and to Dr Raman's certificate. The Tribunal was entitled to have regard to all of the material before it, not just the medical evidence. Earlier in his reasons the Commissioner referred to the worker's statement during the hearing that he had been symptom free until he stepped on a rock at work in October 2014.  That account is consistent with what he told Dr Ruttenberg. Although he did not state that he took what the worker told him into account in his reasoning, it was material to which the Tribunal was entitled to have regard in assessing the existence and strength of the employer's case. It supported an injury in the primary sense, but not a recurrence. Moreover, the employer had no opportunity to test or challenge the account. Dr Raman's certificate refers to the 2010 injury to the right medial meniscus and to a recurrence, but contains nothing which indicates that the recurrence is contributed to by the worker's employment.

3. The Commissioner reviewed the reports of Professor Einoder and Dr Ruttenberg. The Commissioner referred to Professor Einoder's opinion that the worker suffered from a medial meniscus injury which was related to the 2010 injury. The Commissioner reasoned that Professor Einoder "has not identified any factor outside the worker's employment, which may have 'caused or contributed to the current status of his right knee'." With respect to the Commissioner, his statement does not correctly represent Professor Einoder's opinion when read as a whole, and does not address the correct question. The Commissioner refers to Professor Einoder's statement that the worker told him that "in the preceding months he had done some unaccustomed excessive walking on uneven ground and developed pain in his right knee joint" which "gradually became associated with swelling and caused him to limp" as if it corroborates the worker's claim of a work injury on 2 October 2014 when it does not, and is arguably inconsistent with it. Although Professor Einoder's report does not expressly state to the contrary, it contains nothing which attributes employment as a causative or contributing factor to a recurrence. It is possible that the history he was given is incompletely or inaccurately recorded, but the terms of it raise arguable issues. His attribution of the "current problem" to the "2010 problem" is qualified. Nowhere in his discussion of the contents of Professor Einoder's report does he address the question of whether a reasonably arguable case exists about whether employment is not only causally related, but is the major or most significant factor.

4. The Commissioner referred also to Dr Ruttenberg's report in support of his reasoning. As with Professor Einoder, the Commissioner again asserts that Dr Ruttenberg "does not identify any factor outside of the worker's employment which may have caused his current injury". Again, I have a different view about what should have been be made of the report. Dr Ruttenberg's assertion that the worker's employment is the major or most significant contributing factor to a medial meniscus injury is based, is expressed to be on the assumption that "if indeed there was sudden force and he developed an acute onchronic condition and tear of the right medial meniscus". That opinion refers to an injury in the primary sense, not a recurrence. His opinion refers to the pathology being "in the context of may well be degenerative change". Dr Ruttenberg also refers to the variance between the history given to him and the history recorded by Professor Einoder, and the terms of the medical certificate, and suggests that an MRI scan could assist in clarifying "whether he suffered a new injury or whether indeed, the changes are all pre-existing and relate either to the previous injury or degeneration that is present". Dr Ruttenberg said little or nothing about the cause of the gradual increase in symptoms described in the history recorded by Professor Einoder.

5. It seems to me that it must follow from the evidence of Professor Einoder and Dr Ruttenberg that it was reasonably arguable that circumstances other than employment may have contributed to the increase or intensification of the symptoms suffered by the worker. One was the natural progression of the effects of the pre-existing injury. Another is a state of affairs, incident or incidents unrelated to employment. Taken together, the evidence that employment was the major or most significant contributing factor to recurrence of a pre-existing injury was sufficiently equivocal that it could not be said that the employer did not have a reasonably arguable case. The Tribunal reached a conclusion which was not reasonably open to it. This ground succeeds.    

Ground 2

1. Ground 2 reads:

   "The learned Commissioner erred in law in failing to determine that the evidence established a justiciable or contestable issue, namely, whether the worker's injury and resultant incapacity were properly characterised as a recurrence of a pre-existing injury or whether, at a hearing, it would be open to a Commissioner to conclude that the worker's November 2010 injury caused a vulnerability or pre-disposition to the development of further symptoms or incapacity such that, on ordinary causation principles, it could not be concluded that the symptoms and incapacity first certified on 10 November 2014 resulted from the worker's November 2010 injury."

2. This adds little to the first ground, but for the same reasons the ground is made out.

Ground 3

1. Ground 3 reads:

   "The learned Commissioner erred in law in determining it was uncontestable that the worker suffered from a pre-existing injury when on the evidence no such injury was extant at the time he developed his further symptoms and incapacity."

2. This adds nothing to the first two grounds. Without more, this ground would not succeed. The evidence that the worker had been asymptomatic since his recovery from the previous surgery was just one part of the evidence which the Tribunal was required to consider, and, by itself, would not justify the finding that the employer had a reasonably arguable case. This ground fails.

Ground 4

1. Ground 4 reads:

   "The learned Commissioner erred in law in failing to place any weight or any sufficient weight, and thereby in failing to determine that the employer had established a reasonably arguable case in relation to the issue of liability, upon the opinion of Professor Einoder that the worker suffered from a medial meniscus injury which resulted from his November 2010 injury."

2. As with the previous ground this adds nothing to the first two grounds. Without more, it would not succeed. Professor Einoder's report was just part of the evidence, and I have dealt with what was to be made of it in my reasons for allowing ground 1.

Ground 5

1. Ground 5 reads:

   "(5)      The learned Commissioner erred in law in that he made a determination which no Tribunal properly instructed as to the facts and the law could have reached having regard to the evidence and a proper application of the principles established in St Helens Oysters Pty Ltd v Coatsworth [2007] TASSC 90."

2. For the reasons given for allowing ground 1, this ground is made out. I find that the conclusion which the Tribunal must have reached, that a reasonably arguable case concerning the liability of the employer to pay compensation to the worker did not exist, was not reasonably open to it and thus an error of law.

Ground 6

1. Ground 6 reads:

   "(6)      The learned Commissioner erred in law by finding, and utilising as part of his reasoning process, that Professor Einoder did not 'identif(y) any factor, outside the worker's employment, which may have caused or contributed to the current status of his right knee' (at [8]) when Professor Einoder was provided with the history that 'Greg advised me that in the preceding months he had done some unaccustomed excessive walking on uneven ground and developed pain in his right knee joint … (which) gradually became associated with swelling and caused him to limp'."

2. As with ground 4, this ground adds nothing. Professor Einoder's report was just part of the evidence, and I have dealt with what was to be made of it in my reasons for allowing ground 1.

Ground 7

1. Ground 7 reads:

   "(7)      The learned Commissioner erred in law in failing to determine a reasonably arguable case with regard to the issue of liability on the basis of factual discrepancies in relation to the causation of the worker's injury."

2. I have dealt with the issues raised by this ground when dealing with ground 1. The discrepancies in facts recorded in the claim form, the medical certificate and the medical reports of Professor Einoder and Dr Ruttenberg formed part of the reason for allowing ground 1.

Result and conclusions

1. I find that grounds 1, 2 and 5 of the notice of appeal are made out. The appeal is allowed. The Tribunal should have determined under s 81A(3)(c) and (d) that compensation and the cost of benefits not be paid by the employer. However, taking into account the lapse of time since the making of those orders I will hear counsel before determining what orders I should make.