Miller v Secretary, Department of Communities and Justice

Court of Appeal (NSW)|2022-06-01|Before: Ward P, Brereton JA, Mitchelmore JA

ller v State of New South Wales [2018] NSWCA 152 Miller v The State of New South Wales [2017] NSWWCC 66 O'Brien v Tanning Research Laboratories Inc (1988) 14 NSWLR 601 Orellana-Fuentes v Standard Knitting Mills Pty Ltd (2003) 57 NSWLR 282; [2003] NSWCA 146 Port of Melbourne Authority v Anshun Pty Ltd (1981) 147 CLR 589; [1981] HCA 45 Rogers v The Queen (1994) 181 CLR 251; [1994] HCA 42 Salmon Street Ltd (in liq) v Jorgensen (1991) 56 SASR 158 Secretary, Department of Communities and Justice v Miller [2020] NSWWCCPD 38 Secretary, Department of Communities and Justice v Miller [2020] NSWWCCPD 57 Southern Tablelands Health Service v Solomon (1999) 19 NSWCCR 235 Stephenson v Return to Work Corporation of South Australia (2019) 134 SASR 141; [2019] SASCFC 89 Thompson v George Western Foods Ltd (1990) 6 NSWCCR 370 Timbercorp Finance Pty Ltd (in liq) v Collins (2016) 259 CLR 212; [2016] HCA 44 Tomlinson v Ramsey Food Processing Pty Ltd (2015) 256 CLR 507; [2015] HCA 28 VACC Insurance Co Ltd v BP Australia Ltd (1999) 47 NSWLR 716; [1999] NSWCA 427 Category: Principal judgment Parties: David Miller (First Appellant) Terren Tuhi (Second Appellant) Department of Communities and Justice (Respondent) Representation: Counsel: D Hooke SC with SH Hartford Davis (Appellants) PM Morris SC with L Morgan (Respondent)

Solicitors: Stacks Law Firm Southern (Appellants) Moray & Agnew Lawyers (Respondent) File Number(s): 2021/00299055 Publication restriction: Nil Decision under appeal Court or tribunal: Personal Injury Commission Citation: [2021] NSWPICPD 29 Date of Decision: 23 September 2021 Before: Deputy President M Snell File Number(s): A2-2472/19

[Note: The Uniform Civil Procedure Rules 2005 provide (Rule 36.11) that unless the Court otherwise orders, a judgment or order is taken to be entered when it is recorded in the Court's computerised court record system. Setting aside and variation of judgments or orders is dealt with by Rules 36.15, 36.16, 36.17 and 36.18. Parties should in particular note the time limit of fourteen days in Rule 36.16.]

[This headnote is not to be read as part of the judgment] The late Ms Moori Miller was employed by the Department of Communities and Justice at Nynghana Home Care at Brewarrina in North-Western New South Wales. Ms Miller was known to be an asthmatic. On 15 April 2011, while driving a community bus from Brewarrina to Dubbo in the course of her employment, Ms Miller suffered a severe asthma attack. After about 30 minutes, the severity of the attack caused anoxia and cardio-pulmonary arrest. Ms Miller was taken to Nyngan Hospital, where she was pronounced dead. Successive claims for compensation were made first by Mr David Miller, Ms Miller's husband, and then by Mr Miller and Mr Terren Tuhi, Ms Miller's son, jointly. The first claim for compensation particularised the relevant injury as an "asthma attack". In the first of a number of proceedings in the Workers Compensation Commission (as it then was) and then the Personal Injury Commission, an Arbitrator was not satisfied that Ms Miller's employment was a "substantial contributing factor" to the asthma attack, because Ms Miller had suffered from asthma all of her life and the driving of the bus on 15 April 2011 did not catalyse the asthma attack in question. In the second claim for compensation, the "injury" was pleaded as anoxia and cardiac arrest arising in the course of Ms Miller's employment. An Arbitrator found that the relevant "injury" was cardio-pulmonary arrest and found that that injury was causally connected to Ms Miller's employment by reason of the remote location in which she was required to work insofar as that location deprived her of access to the kind of treatment for her asthma attack that would have prevented the cardio-pulmonary arrest and death. On appeal to the President of the Commission, it was held that the Arbitrator had failed to address (inter alia) the question of Anshun estoppel, which was remitted to a different Arbitrator for determination. The Arbitrator upheld the Anshun defence, as did the Deputy President on appeal. The appeal to this Court was confined to a single issue, being the following question of law: (1) Is the application of the common law doctrine of estoppel associated with Port of Melbourne Authority v Anshun Pty Ltd (1981) 147 CLR 589; [1981] HCA 45 as a defence to statutory entitlements consistent with the scheme of the Workers Compensation Act 1987 (NSW) (1987 Act) and the Workplace Injury Management and Workers Compensation Act 1998 (NSW) (1998 Act)?

The Court (per Ward P, Brereton JA and Mitchelmore JA agreeing) held, dismissing the appeal [128] (Ward P), [133] (Brereton JA), [138] (Mitchelmore JA):

As to issue (1):

There is no reason in principle why Anshun estoppel ought not be applicable to the legislative schemes established by the 1987 and 1998 Acts: [127] (Ward P). One cannot expect there necessarily to be a perfect alignment between a statutory framework and common law principles, here the 1987 and 1998 Acts and the principle of Anshun estoppel. Mere difficulty in the application of such principles to the statutory framework should not preclude any attempts to reconcile the two in the absence of an express exclusion of common law principles by the legislature, or manifest inconsistency between the statute and those principles. No such exclusion or inconsistency exists here: [127] (Ward P). Moreover, the application of Anshun is consistent with statutory provision for dismissal of vexatious proceedings in the compensation jurisdiction: [134] (Brereton JA). Lambidis v Commissioner of Police (1995) 37 NSWLR 320, applied.
Courts have consistently applied Anshun estoppel in the context of the 1987 and 1998 Acts in situations where the dispute concerns the whole issue of liability to pay compensation as opposed to disputes where compensation was claimed for separate entitlements arising from the one incident: [120]-[121] (Ward P), [135] (Brereton JA). Salmon Street Ltd (in liq) v Jorgensen (1991) 56 SASR 158, distinguished.
Insofar as the 1998 Act provides that disputes are to be determined according to "equity, good conscience and the substantial merits of the case without regard to technicalities or legal forms", this does not preclude the application of Anshun estoppel to the legislative scheme. Anshun estoppel is neither a formality, nor a technicality, but a principle of law of fundamental importance which bears squarely upon the rule of law and issues of fairness and justice: [123] (Ward P).

Judgment

WARD P: This is the latest in a succession of applications relating to claims for compensation, following the death of the late Mrs Moori Miller (the deceased), by members of the deceased's family. The first appellant was the deceased's husband; the second appellant, her son.
Briefly, the circumstances in which those compensation claims arose were that the deceased, who was employed by the Department of Communities and Justice (Department) at Nynghana Home Care at Brewarrina in North-Western New South Wales, and was known to be an asthmatic, experienced a severe asthma attack on 15 April 2011, while driving a community bus from Brewarrina to Dubbo in the course of her employment. After about 30 minutes, the severity of the attack caused anoxia and cardio-pulmonary arrest. The deceased was taken to Nyngan Hospital, where she was pronounced dead. The deceased was 48 years old at the time of her death.
Successive claims for compensation were made (as described in more detail shortly). The present proceeding is an appeal pursuant to s 353(1) of the Workplace Injury Management and Workers Compensation Act 1998 (NSW) (the 1998 Act) from a decision of the Personal Injury Commission, constituted by Deputy President Snell (Miller v Secretary, Department of Communities and Justice (No 9) [2021] NSWPICPD 29 (Miller (No 9)). The appeal is confined (as it must be) to a question of law, namely: Is the application of the common law doctrine of estoppel associated with Port of Melbourne Authority v Anshun Pty Ltd (1981) 147 CLR 589 as a defence to statutory entitlements consistent with the scheme of the Workers Compensation Act 1987 (NSW) (1987 Act) and the 1998 Act?
The appellants emphasise that there is an extant finding in their favour that they are entitled to no-fault statutory compensation under ss 25 and 26 of the Workers Compensation Act 1987 (NSW) (the 1987 Act). The effect of the decision in Miller (No 9) is that the appellants are barred from recovering that statutory entitlement by reason of the operation of an Anshun estoppel (eponymously named after the decision in Port of Melbourne Authority v Anshun Pty Ltd (1981) 147 CLR 589; [1981] HCA 45 (Anshun)). The appellants accept that there can be no challenge to the unreasonableness finding underpinning the Anshun defence.
If the appeal is allowed, the appellants seek the remittal of the matter to the Personal Injury Commission for determination of outstanding issues.

First claim for compensation (proceeding no 5831 of 2016)

As noted above, the deceased died on 15 April 2011. The first claim for compensation (proceeding no 5831 of 2016) was made by application dated 10 November 2016 by the deceased's husband, Mr Miller, to the then Workers Compensation Commission. The application was made pursuant to ss 25 and 26 of the 1987 Act. The deceased's dependent son (the second appellant in the present proceeding) was a respondent to the first application.
The claim form defined the deceased's "injury" as "an asthma attack". The injury was particularised as a disease and the claim was brought as a claim for "aggravation, acceleration, exacerbation or deterioration" of a disease pursuant to s 4(b)(ii) of the 1987 Act. On the question of causation, the relevant counterfactual analysis involved the contention that a better outcome for the deceased would have ensued had the asthma attack occurred in a centre such as Brewarrina rather than in the remote location in which the deceased was at the time (in the course of her employment).
In a determination made on 21 March 2017 in Miller v The State of New South Wales [2017] NSWWCC 66 (Miller (No 1)), Arbitrator Batchelor was not satisfied that the deceased's employment was a "substantial contributing factor" to the "injury" (i.e., as defined, the "asthma attack"), within the meaning of s 9A(1) of the 1987 Act, because the deceased had suffered from asthma for all of her life (see at [8]). The Arbitrator noted that it was not in dispute that the driving of the bus on 15 April 2011 did not bring on the asthma attack (see at [107]).
Arbitrator Batchelor found that the cause of the deceased's injury was a pre-existing medical condition which was not aggravated by her employment (see at [112]). The Arbitrator (in a passage later endorsed by this Court) observed that in addressing a causal connection between employment and injury, there must be a focus on the injury relied upon by the applicant (see at [107]); and said that, while the deceased's death may have been contributed to by the remoteness of the location, her death was not the injury she sustained (see at [107]). Thus, the Arbitrator concluded that, while the location of events may have been a substantial contributing factor to the deceased's death "it was not such a factor to her injury" (see at [110]).
The appellants say that the first application thus failed by reason of a misidentification of the "injury" and insufficient attention to the causal requirement in the presentation of the claim (a problem unable to be rectified on appeal).
In Miller v State of New South Wales [2017] NSWWCCPD 38 (Miller (No 2), Mr Miller sought leave to adduce evidence from Dr Jennings and Professor Fulde (the same evidence later relied upon in the second compensation application) to the effect that, had the deceased been able to receive appropriate treatment of the acute asthma attack in a timely manner, her condition may never have deteriorated to cardiac arrest and anoxia, and the deceased may have survived. The application to adduce fresh evidence was rejected (by determination made on the papers on 1 September 2017) by Parker ADP at [51], who dismissed an appeal from the decision of Arbitrator Batchelor on the basis that no error had been demonstrated in his reasons, noting that the injury (being the asthma attack) was not in any sense caused by the "location at which the deceased was at the time and what she was doing driving the bus" (see at [124]; see also [83] and [113]).
In Miller v State of New South Wales [2018] NSWCA 152 (Miller (No 3)) this Court (McColl, Meagher and Leeming JJA) dismissed an appeal from the decision of Parker ADP (see at [39]). Mr Miller had there sought to identify the injury as "the anoxia or the cardiac arrest" (see at [16]), but this Court observed that this had not been the injury propounded before Parker ADP; and held that there could be no error "still less error in point of law" in failing to make findings in accordance with a case which was not put before Parker ADP (see at [16]; [19]; and [30]). In Miller (No 3), this Court said (at [37]) that: On no view of the meaning of section 9A could the deceased's employment be causally connected with any formulation of the injury unless the deceased would more likely have rapidly appreciated that she was suffering a severe asthmatic attack. …

Second claim for compensation (proceeding no 2472 of 2019)

The second claim for compensation (proceeding no 2472 of 2019) was commenced by application dated 22 May 2019 to the Workers Compensation Commission. The second appellant was this time named as a claimant. On this application, the "injury" was pleaded as anoxia and cardiac arrest arising in the course of employment, per s 4(a) of the 1987 Act. The insurer disputed liability (by notice issued under s 78 of the 1998 Act) (see at [4]), among other things on the basis that: … the claim could not be maintained by reason of estoppels - including an issue estoppel, or in the alternative a res judicata estoppel, or in the alternative an estoppel in the nature of that described by the High Court in Port of Melbourne Authority v Anshun Pty Ltd [1981] HCA 45, or in the alternative a privity of interest estoppel, created by: • The determination of Arbitrator Brett Batchelor dated 21 March 2017 in WCC 5831/16; or in the alternative; • The determination of Acting Deputy President Jeffery (sic) Parker SC dated 1 September 2017 in WCC A1-5831/16; or in the alternative; • The determination of NSW Court of Appeal dated 12 July 2018 (bearing medium neutral citation [2018] NSWCA 152).
The appellants relied in support of this application on the additional evidence of Dr Jennings and Professor Fulde that had been rejected by Parker ADP in Miller (No 2). The claim was presented on the basis that the deceased's employment had taken her away from her normal workplace, where it was said that the additional evidence established that it was more likely than not that the deceased would have survived the asthma attack (see at [33]). It is noted by the respondent that there was no additional evidence adduced relevant to the issue whether, in the relevant counterfactual, the deceased would have appreciated that she was suffering a severe asthma attack and then acted appropriately (but that Arbitrator Wynyard nevertheless concluded that the deceased would have sought medical assistance within the window of opportunity).
In the present appeal, the appellants emphasise the dispositive factual finding concerning the causality of the deceased's death made by Arbitrator Wynyard in Miller v Secretary, Department of Communities and Justice (Workers Compensation Commission (NSW), Arbitrator Wynyard, 11 October 2019, unrep) (Miller (No 4)), namely that: I am satisfied that, had the deceased suffered her asthma attack whilst she was in her office at Brewarrina 30 minutes before she suffered her cardio-pulmonary arrest, she would probably have survived. I accept the evidence of Dr Jennings and Professor Fulde, which indeed accords with common sense, in that regard. The place of the injury, being in a remote location following her driving in the course of her employment from Brewarrina to Dubbo and thence through Nevertire to a point about 10km from Nyngan, was a substantial contributing factor to her cardio-pulmonary arrest. The location deprived the deceased of the opportunity to have either the means or the time to avail herself of appropriate treatment.
Thus, Arbitrator Wynyard accepted that the relevant "injury" was cardio-pulmonary arrest and found that that injury was causally connected to Ms Miller's employment by reason of the remote location in which she was required to work; the causal connection being that the remote location deprived her of access to the kind of treatment for her asthma attack that would have prevented the cardio-pulmonary arrest and death from occurring (see at [116]). (The appellants here emphasise the importance which the evidence of Dr Jennings and Professor Fulde assumed in those findings.)
Arbitrator Wynyard determined that the appellants were not estopped from bringing the action, essentially because: the pleaded injury was different, the new evidence satisfied him of causation on that injury, and there was no inconsistency with the determination of Arbitrator Bachelor (see at [117]-[121]).
In Secretary, Department of Communities and Justice v Miller [2020] NSWWCCPD 38 (Miller (No 5)), Phillips P allowed an appeal from the decision of Arbitrator Wynyard. Phillips P found no error in Arbitrator Wynyard's treatment of the question of injury or causation (see at [176]) and hence those findings were undisturbed on appeal. Phillips P observed that the medical evidence contemplated that "it was possible that the deceased would have had a different outcome to the tragic event which actually occurred"; and, accordingly, the decision-maker could "without error and in reliance upon other evidence, find the matter proven to the required standard" (see at [173]-[174]).
Phillips P rejected the res judicata defence, on the basis that the s 4(a) injury determined in the first application (being proceeding no 5831 of 2016) and the s 4(b)(i) "disease claim" in the second application were "separate and distinct causes of action" (see at [154]).
However, Phillips P considered that Arbitrator Wynyard had erred in his treatment of the estoppel defences, concluding that he had not grappled properly with the issue estoppel question (see at [160]); and he had not undertaken the evaluative assessment required in a claim of Anshun estoppel (see at [197]).
Phillips P remitted the matter to a different Arbitrator. An issue then arose as to what precisely had been remitted.
In Miller v Secretary, Department of Communities and Justice (Workers Compensation Commission (NSW), Arbitrator Harris, 1 July 2020, unrep) (Miller (No 6)), Arbitrator Harris directed the parties to lodge an application for reconsideration of the decision in Miller (No 5). The reconsideration application was then determined by Phillips P on the papers in Secretary, Department of Communities and Justice v Miller [2020] NSWWCCPD 57 (Miller (No 7)), clarifying that only the issue estoppel and Anshun estoppel defences had been remitted to the Arbitrator.
In Miller and Tuhi v Secretary, Department of Family and Community Services [2021] NSWWCC 22 (Miller (No 8)), Arbitrator Harris dismissed the "issue estoppel defence" but upheld the Anshun defence. In relation to issue estoppel, Arbitrator Harris held that the relevant finding that determined proceeding no 5821 of 2016 was "for a different injury occurring at a slightly different time, some 30 minutes later" (see at [68]). In relation to Anshun estoppel, Arbitrator Harris made a finding (which the appellants concede is not amenable to challenge on this appeal) that the appellants "had knowledge of the existence of the s 4(a) injury during the hearing in [Miller (No 1)]" (see at [108]). The respondent noted that no evidence was led before Arbitrator Harris to explain why the s 4(a) injury was not argued in the earlier proceeding (see at [128]). Arbitrator Harris rejected the appellants' explanation for not arguing the s 4(a) injury on the first claim, saying that it did "not stand up to any proper analysis" (see at [133]). Arbitrator Harris concluded "that it was unreasonable that the [appellants] did not pursue the s 4(a) injury in [Miller (No 1)] and that the Anshun estoppel defence is established" (see at [154]).
In Miller (No 9), the decision now impugned, Snell DP confirmed the decision of Arbitrator Harris. Snell DP rejected the challenge to Arbitrator Harris' factual finding regarding the state of the appellants' knowledge at the time of Miller (No 1) (see at [109]-[110]). Snell DP also rejected the challenge to the unreasonableness finding, saying that he could not see that the Arbitrator erred in adopting an approach consistent with that of the High Court in Anshun (see at [182]) (reasoning which the appellants note assumed that the Anshun principle applied in the Commission).
Thus, the appellants say that, subject to Anshun estoppel (which has been determined against them in Miller (No 7) and Miller (No 8); and which they cannot now challenge), they have established statutory entitlements to compensation under ss 25 and 26 of the 1987 Act.

Legislative framework

The legislative scheme under the 1987 Act, which was in force at the time of the deceased's death, for compensation for the estate and dependants of a deceased worker who dies in the course of employment, encompasses the definition of "injury" (see s 4(a)) as being, relevantly, "personal injury arising … in the course of employment". By s 4(b)(ii), the term "injury" includes what is now known as "disease injury", which means the aggravation, acceleration, exacerbation or deterioration of a pre-existing disease, but only "where the employment was a contributing factor to the aggravation, acceleration, exacerbation or deterioration". By s 9A(1), compensation is payable if "the employment concerned was a substantial contributing factor to the injury".
By the time of the second application, the relevant legislation was the 1998 Act as it was in force as at 22 May 2019. From 1 March 2021, the Workers Compensation Commission was abolished, and the matter became a matter within the Workers Compensation Division of the Personal Injury Commission.
The jurisdiction of the Commission is created and defined by the 1998 Act, which established the Workers Compensation Commission of New South Wales (s 366(1)) and invested it with "exclusive jurisdiction to examine, hear and determine all matters arising under [the 1998 Act] and the 1987 Act" (see s 105(1) of the 1998 Act). Emphasis is placed by the appellants on the fact that the jurisdiction of the Commission is relevantly confined by the claim-based notification and payment regime (which they identify as the cardinal features of the legislative scheme).
The process for making a claim for compensation as set out in the 1998 Act encompasses the following.
An injured worker is to give notice of the injury to the employer as soon as possible after the injury happens (s 254(1)), and the notice must state "the cause of the injury" (s 255(1)(b)). Compensation cannot be recovered under the 1998 Act unless a "claim for the compensation has been made within 6 months" of either the injury or the date of death (s 261(1)). A claim must be made in accordance with the Workers Compensation Guidelines (s 260(1)), and must include, inter alia, "full details" including of the "injury received by the claimant" (s 282(1)(a)).
Within 21 days after a claim for weekly payments is made, the person on whom the claim is made must "determine the claim" (by accepting liability and commencing payments, or by disputing liability) (s 274(1)(a) and (b)). Thus, it is said that the "claim" itself is to be determined by the employer (or its insurer) in response to a statutory notice and not by the Commission.
The insurer must give notice of any decision to dispute a claim or any aspect of a claim, or to discontinue a weekly payment (s 78(1)(a) and (b)). A worker may request an insurer to review a claim, or any aspect of a claim, that is disputed, at any time before the dispute is referred for determination by the Commission (see ss 287A(1)(b) and (2)). (The appellants note that, no doubt, the majority of entitlements are determined in this way - i.e., before any "dispute" reaches the Commission.)
The jurisdiction of the Commission is relevantly attracted only by "a dispute in connection with a claim for compensation" (s 287(1)). The jurisdiction is engaged if, and to the extent that, any party to a "dispute about a claim" refers such a "dispute" to the Registrar of the Commission "for determination by the Commission" (s 288(1)). The appellants place weight on the fact that a "dispute" can only be referred to the extent that it "concerns only matters previously notified as disputes" (s 289A(1)).
The objectives of the Commission include to "provide a fair and cost effective system for the resolution of disputes" (s 367(1)(a)). The Commission is constituted of a President, Deputy Presidents, a Registrar and Arbitrators (see s 368(1)). For the purposes of any proceedings, the Commission is to be constituted by an Arbitrator (s 375(1)). Section 369(3) provides that a person is eligible to be appointed as an Arbitrator only if the person: (a) is an Australian lawyer (but the Arbitrator need not have five years' standing, which is required by s 369(2)(b) for the appointment of a Deputy President); or (b) "has such qualifications, skills or experience as may be determined by the Minister".
If a dispute is determined by the Commission, the Commission must issue "a certificate as to the determination", together with a brief statement attached to the certificate "setting out the Commission's reasons for the determination" (see ss 294(1) and (2)). Section 350(1) provides that "a decision of the Commission under the Workers Compensation Acts is final and binding on the parties and is not subject to appeal or review". (The appellants concede that, subject to their submissions regarding the entirety of the scheme established by the 1987 and 1998 Acts, this is the sort of provision that is capable of attracting the doctrines of res judicata and cause of action or issue estoppel, which extend "to the decision of any tribunal which has jurisdiction to decide finally a question between the parties, even if it is not called a court, and its jurisdiction is derived from statute", however the appellants distinguish this from Anshun estoppel - citing Administration of Territory of Papua and New Guinea v Guba (1973) 130 CLR 353; [1973] HCA 59 (Papua and New Guinea v Guba) at 453 per Gibbs J (as his Honour then was) with whom Menzies and Stephen JJ agreed.)
Section 354(3) of the 1998 Act requires the Commission to act according to "equity, good conscience and the substantial merits of the case without regard to technicalities or legal forms". (That said, the appellants say that the history of this matter exposes the importance of precisely identifying the "injury", in order to establish the requisite causal connection between injury and employment.)
The appellants note the limited nature of the appeal rights. A party may appeal to the Commission constituted by a Presidential member against a decision in respect of the dispute by an Arbitrator (s 352(1)). Appeals lie only from error (of fact, of law or of discretion), and are limited to the correction of any such error (the appeal is not a review or new hearing) (s 352(5)). On appeal, a decision can be confirmed or revoked, and a new decision issued in its place, or the matter may be remitted back to an Arbitrator for determination in accordance with any decision or direction of the Commission (s 352(7)). An appeal to this Court from a presidential member of the Commission (of which the present appeal is an example) is limited to a "point of law" (s 353(1)).
The "rights in issue" are created by the 1987 Act. Section 9(1) of the 1987 Act provides relevantly that the dependants of a deceased worker "shall receive compensation from the worker's employer in accordance with this Act". The relevant rights the subject of the claims in the present case are created by ss 25 and 26 of the 1987 Act. Section 25 states the amount of compensation that "shall be" "payable by the employer under this Act", in the event that "death results from an injury". The compensation payable includes a "lump sum death benefit" (s 25(1)(a) of the 1987 Act), and a weekly benefit for dependent children (s 25(1)(b) of the 1987 Act) which can be commuted to a lump sum payment (s 87E(1) of the 1987 Act). Additionally, the employer "must pay additional compensation equal to reasonable funeral expenses not exceeding $9,000" (s 26 of the 1987 Act). The payments are required to be paid by cash, cheque or direct credit (s 83(1) of the 1987 Act).
Section 25 of the 1987 Act provides for a benefit "if death results from injury". "Injury" is defined by s 4 to include both "personal injury" and the "aggravation acceleration, exacerbation or deterioration" of a disease. As at April 2011 (the date of the death of the deceased), s 9A provided that no compensation is payable with respect to an injury (as defined by s 4) "unless employment was a substantial contributing factor to the injury".

Appellants' submissions

The appellants submit that the legislative framework of the 1987 Act is not consistent with the application of the common law principle of Anshun estoppel as a defence to defeat a statutory entitlement; and they argue that the principle of Anshun estoppel is not available for use to defend applications brought before the Commission (cf the conclusion in Miller (No 5) at [187]).
In this regard, the appellants place emphasis on the recognition in the authorities (see below) that Anshun estoppel has the status of a "true estoppel". It is submitted that the relevant enquiry is therefore not as to the finality of a decision of the Commission (as it is said would be the required focus in determining whether issue estoppel or res judicata could be applied) but instead to whether the statutory regime is consistent with the importation of a non-statutory common law defence.
The appellants argue that the focus of Anshun estoppel on "reasonableness" is to be understood as a prism for analysing the conscience of the litigant, consistently with the ordinary principles of estoppel. Reference is made to British Airways Board v Laker Airways Ltd [1985] AC 58, where Lord Diplock at 81 referred to different categories of a "legal or equitable right not to be sued", including a contractual right (for example an exclusive jurisdiction clause), and other defences that can be "given anticipatory effect as a right not to be sued", of which his Lordship said: Of such defences it is not difficult to point to a number of examples most of them equitable in historical origin, such as estoppel in pais … promissory estoppel, election, waiver, standing by, laches, blowing hot and cold - to all of which the generic description of conduct that is 'unconscionable' in the eye of English law may be given.
It is noted that the above passage was cited alongside the decision in Anshun by the plurality in CSR Ltd v Cigna Insurance Australia Ltd (1997) 189 CLR 345; [1997] HCA 33 at 394, their Honours (Dawson, Toohey, Gaudron, McHugh, Gummow and Kirby JJ) saying that the bringing of proceedings "with respect to one claim" might "properly to be seen, in the circumstances of the case, as an election ... not to proceed on another claim ... thus giving rise to an estoppel by conduct such that it would be unconscionable for that other claim to be pursued". In VACC Insurance Co Ltd v BP Australia Ltd (1999) 47 NSWLR 716; [1999] NSWCA 427 Fitzgerald JA commented (at [24]) on "the present uncertainty concerning the nature and scope of Anshun estoppel".
The appellants point out that whether an issue estoppel is able to arise in the context of any particular statutory regime is to be answered "by reference to the powers and duties of the particular tribunal and what it has in fact done in the particular case" (and in that context it is important to determine whether the relevant tribunal has jurisdiction to decide finally a question arising between parties) but that, given the nature of Anshun as a "true estoppel", the finality of a tribunal's decision does not conclusively demonstrate whether Anshun can apply. Instead, the appellants submit that the question whether Anshun can apply is to be answered by a detailed assessment of whether the statutory scheme is consistent with the importation of a (non-statutory) common law defence.
The appellants say that an important exception to the finality of the Commission's decisions is that the Commission may "reconsider any matter that has been dealt with by the Commission and rescind, alter or amend any decision previously made or given by the Commission" (referring to s 350(3) of the 1998 Act; see also s 378 of the 1998 Act in respect of the Registrar or an Appeal Panel, the latter in respect of a medical dispute). It is noted, by way of example, that decisions can be varied to bring them into line with a subsequent opinion of the Commission on a question of law (s 351(6)(b) of the 1998 Act). The appellants also point to Miller (No 6) as an example of this, where a decision was re-issued to clarify what it was initially intended to convey.
The appellants identify a number of features of the statutory scheme which they maintain are inconsistent with the operation of the Anshun principle.
First, they argue that the operation of an Anshun defence is not harmonious with the claim-based notification and payment regime which the legislative scheme embodies. Emphasis is placed on the fact that the Commission does not have jurisdiction except to resolve a "dispute" about a notified claim. It is submitted that a jurisdiction of that kind is inconsistent with an implied common law obligation to raise any other claims that the party should reasonably bring forward simultaneously because the jurisdiction of the Commission will not be attracted about such other claims unless and until there is a "dispute" on a notified "claim".
The appellants submit that the features of the 1987 Act and the 1998 Act are analogous to the claim-based structure of the repealed Workmen's Compensation Act 1971 (SA), and they refer to the decision of the Full Court of the Supreme Court of South Australia in Salmon Street Ltd (in liq) v Jorgensen (1991) 56 SASR 158 (Salmon Street) for the proposition that Anshun estoppel does not apply in that statutory regime, because of the "markedly" different nature of the rights and the claim resolution process (see at 161 per King CJ, with whom Cox and Bollen JJ agreed).
In particular, it is noted that the Court there noted: (at 161), that under the legislation there is no single cause of action for compensation for injury - instead, a worker may be "be compensable separately in respect of disparate injuries sustained in the same accident and may pursue separate claims in respect of such injuries"; (at 162) that the remedy conferred by the legislation is not an action to recover compensation; instead, the "ordinary method by which compensation will be obtained" (see at 162) is by the giving of a notice claiming compensation, triggering an obligation in the employer to commence weekly payments "as soon as possible", and provision for registration of agreements for lump sum compensation; and (at 162) that the jurisdiction conferred on the Industrial Court is only to determine "any question or dispute", the "essential point" being that the jurisdiction as envisaged by the Act is "to determine questions and disputes arising in the compensation process rather than to be the vehicle for the pursuit of claims for the recovery of compensation". There, that role of the Industrial Court was held to be incompatible with the concept, central to Anshun estoppel, "that where a dispute is brought to the Court as to liability for a particular injury, the worker is obliged to raise all other injuries arising out of the accident notwithstanding that they may not be in dispute at all" (see at 162).
The Full Court there held that an injured worker commencing a claim in the Industrial Court "is not required to raise in the proceedings all injuries or impairments which he has sustained in the accident or even all injuries or impairments of which he is then aware" (at 162).
The appellants say that this is reasoning which this Court should follow unless convinced it is distinguishable or plainly wrong (referring in this context to Farah Construction Pty Ltd v Say-Dee Pty Ltd (2007) 230 CLR 89; [2007] HCA 22 at [135] per the Court).
Second, and the appellants place emphasis on this, the appellants point out that there is no provision of the statutory framework which authorises the disqualification of a statutory entitlement by the operation of a non-statutory common law defence. It is noted that s 9(1) of the 1987 Act provides relevantly that the dependants of a deceased worker "shall receive compensation from the worker's employer in accordance with this Act". The appellants argue that the legislative scheme creates a code for compensation entitlements to the exclusion of common law principles. It is said that the importation of a common law Anshun estoppel defence into the scheme of the 1987 Act and the 1998 Act is inconsistent with that particular feature of the legislation. It is noted that in Angeleska (known as Slaveska) v State of Victoria (2015) 49 VR 131; [2015] VSCA 140 at [199], the Victorian Court of Appeal (Warren CJ, Tate JA and Ginnane AJA) has said that Anshun estoppel "operates to prevent a person from bringing a proceeding or particular claims [and] is a serious step: it removes a litigant's right to have the merits of a claim adjudicated". The appellants say that if Anshun is to be imported into the statutory framework, there should be a statutory foundation for that to occur (and here there is none).
Third, the appellants say that there is no statutory restriction on referring disputes to the Commission on the basis (for example) that they have been the subject of previous determinations. Reference is made to s 289 of the 1998 Act, which sets out restrictions on the kinds of dispute that can be referred to the Commission and it is noted that there is no relevant restriction analogous to the Anshun principle which would preclude the referral of a dispute on the basis that it was unreasonable not to have resolved it as part of a previous dispute.
Fourth, the appellant argues that the provisions in the 1998 Act governing the making of claims are inconsistent with the Anshun principle (which classically requires parties "to bring forward their whole case"), referring to s 261(3), which expressly contemplates that multiple claims for compensation may be made at different times "in respect of the injury or death concerned". It is noted that compensation cannot be recovered under the 1998 Act unless a "claim for the compensation has been made within 6 months" either of the injury or the date of death (s 261(1)) but that time ceases to run if "any claim for compensation in respect of the injury or death" is made, "even if the person's claim did not relate to the particular compensation in question" (see s 261(3)). Reference is also made to the provision that, if two or more persons are liable or partly liable in respect of compensation, time ceases to run when a claim is made on any one of those persons (s 261(8)).
Fifth, the appellants point to provisions in the 1998 Act expressly requiring that certain claims be made "at the same time" (which it is said operates inconsistently with Anshun, and would be substantially redundant if the making of a subsequent claim "in respect of the injury or death concerned" was liable to be defeated by Anshun). In this regard, reference is made to s 263(1) of the 1998 Act, which requires that claims "for permanent impairment compensation in respect of an injury must, as far as practicable, be made at the same time". It is submitted that a provision of this kind would be redundant if Anshun were of general application; moreover, it is noted that the provision (which applies only in relation to claims for permanent impairment compensation) applies only "as far as practicable". It is noted that non-compliance produces the result not that the claim is barred (as would occur by application of Anshun estoppel) but instead that the legal practitioner is precluded from recovering of costs "in relation to any such claim made later" in the absence of a "good reason for the claim being made later" (s 263(2) of the 1998 Act). It is submitted that these provisions expressly contemplate that different claims may be made at different times, and attributes a limited consequence to that occurrence; namely, disentitlement to costs.
The appellants also refer to provisions of the same kind in s 65 of the 1998 Act for pre-2001 injuries (s 60A(2)) (referring to s 65(6), s 65(9); and s 66(2A)). The appellants say that these provisions expressly contemplate that there may be multiple claims "in respect of the injury or death", brought at different times, against the same employer (noting that there is a specific and limited consequence applied by the statutory scheme to that kind of inefficiency, namely, cost disentitlement); and argue that these provisions would be substantially (if not entirely) redundant if Anshun applied. It is noted that there is specific provision (cost disentitlement) made in the legislation which is very different from the operation of Anshun.
Sixth, the appellants point to the specific provision in the 1987 Act against double recovery, which they say would be substantially redundant if an Anshun defence was available. It is said that Anshun would typically prevent re-litigation of a dispute in one State or country which had already been determined in another State or country. The appellants say that if it were of general application under this scheme, there would be no need for s 9AC(1) of the 1987 Act, which provides that compensation "is not payable in respect of any matter to the extent that compensation has been received under the laws of a place other than this State". Insofar as s 9AC(2) and (3) provide for the recovery of double-paid compensation, the appellants say that double recovery of the kind contemplated would almost always be incompatible with Anshun; and hence they argue that the fact that the legislature made specific provision of this kind indicates that Anshun is not to apply.
For the same reason, the appellants say that Pt 3, Div 8 of the 1987 Act cannot be reconciled with the application of Anshun. It is noted that that Division makes specific provision for what is to occur in the event that a worker or the worker's dependant is successful in different claims under the 1987 Act at different times (something which it is said would be unnecessary if Anshun were to be applicable). It is noted that s 87B(1) provides that if a person "who is entitled to compensation under this Act has been paid additional or alternative compensation to which this Division applies, the amount of compensation payable under this Act is to be reduced" to that extent. Section 87A(2)(c) includes within the classes of "additional or alternative compensation" to which the Division may apply (subject to prescription by regulations) "any other payments in respect of injuries or death for which compensation is payable under this Act". Thus, the appellants say that Div 8 of Pt 3 specifically contemplates two distinct claims for compensation being determined "under this Act" at different times, and makes provision for reduction (but not barring) to that extent.
The seventh feature to which the appellants point in this context is the specific provision made (in Pt 5 of the 1987 Act) for the circumstances in which prior litigation should disentitle a claimant from statutory compensation, in contrast with the fact that there is no specific provision for or akin to Anshun. It is noted that s 151A(1)(a) of the 1987 Act provides that, if a person recovers "damages" in respect of an injury from an employer "liable to pay compensation under this Act", then the person "ceases to be entitled to any further compensation under this Act in respect of the injury concerned"; and that s 149(1) of the 1987 Act defines "damages" as including "any form of monetary compensation" except, inter alia, "compensation under this Act" that would be payable "if a claim for that compensation were duly made" (ss 149(1)(c) and 149(2) of the 1987 Act). The appellants say that the effect of these provisions is that, if a person recovers damages independently of the 1987 Act, the person "ceases" to be entitled to claim compensation under the 1987 Act; i.e., the legislature saw fit expressly to define the circumstances in which the statutory entitlement would "cease" (namely, only in the event of prior recovery of "damages" and not merely because a prior claim for damages had been made). The appellants say that this tells against the generalised application of Anshun.
Eighth, the appellants note that the Commission is granted a limited statutory power to dismiss proceedings before the Commission on certain grounds (if they have been abandoned, or if satisfied that they are "frivolous or vexatious or otherwise misconceived or lacking in substance", or for any other ground of dismissal specified in the Rules (see the former s 354(7A) of the 1998 Act, and s 54), but that this power does not include a ground analogous to Anshun. The appellants argue that this statutory power of dismissal provides ample power to prevent abuses of the Commission's processes, and to prevent unmeritorious litigants from harassing employers and wasting the Commission's resources with unmeritorious claims. It is noted that there is no statutory power to dismiss a proceeding merely because an issue should reasonably have been litigated in a prior claim.
Ninth, the appellants maintain that the importation of a common law Anshun principle is inconsistent with s 354(1) of the 1998 Act, which provides that proceedings before the Commission "are to be conducted with as little formality and technicality as the proper consideration of the matter permits". It is noted that the Commission is not bound by the rules of evidence, but may inform itself "on any matter in such manner as the Commission thinks appropriate and as the proper consideration of the matter before the Commission permits" (s 354(2)); and that s 354(3) provides that the Commission "is to act according to equity, good conscience and the substantial merits of the case without regard to technicalities or legal forms". The appellants say that, while s 354(3) by itself does not "exclude the application of the rules of substantive law," when read with s 9 of the 1987 Act and the other features of the scheme explored in these submissions, s 354 as a whole is not consistent with a rule which operates to preclude a claimant from an otherwise established statutory entitlement on the basis that they unreasonably failed to identify the "injury" in a certain way as part of a previous claim.
Tenth, it is said that the exclusion of Anshun would be harmonious with the fact that the Commission constituted by an Arbitrator is not exercising judicial power. In that regard, the appellants identify an apparent tension between the decision of the Full Court of the Federal Court (Allsop CJ, Reeves and Derrington JJ) in Commonwealth v Snell (2019) 269 FCR 18; [2019] FCAFC 57 (at [42]-[43], [50]-[51] per the Court) to the effect that res judicata does not apply in federal administrative tribunals and the statement of the High Court in Tomlinson v Ramsey Food Processing Pty Ltd (2015) 256 CLR 507; [2015] HCA 28 (Tomlinson v Ramsey Food Processing) (at [21], per French CJ, Bell, Gageler and Keane JJ) to the effect that the operation of estoppel in relation to judicial determinations is "not confined to an exercise of judicial power [but] also operates in the context of a final judgment having been rendered in other adversarial proceedings". The appellants suggest that these authorities may be able to be reconciled by the proposition that res judicata does not result from a "mere administrative decision", referring to Papua and New Guinea v Guba at 453 per Gibbs J, as his Honour then was. In any event, the appellants argue that the proposition that the Commission constituted by an Arbitrator is not exercising judicial power assists in reinforcing the conclusion that Anshun does not apply.
In that regard, the appellants contend that the Commission constituted by an Arbitrator is exercising a function that is merely administrative, pointing to the following factors. First, that while a decision of an Arbitrator is "final and binding" (s 350(1) of the 1998 Act), it is subject to the important (non-judicial) exception that the Arbitrator has a power to reconsider "any decision" including to bring it in line with a subsequent opinion on a point of law (s 350(3)). Second, that the Commission is unable itself to enforce its own determinations (those determinations being enforceable in "a court having jurisdiction to give judgment for a debt", and being given statutory status as "such a judgment" - see s 362(3) of the 1998 Act). Third, that the power being exercised requires the Commission "to act according to equity, good conscience and the substantial merits of the case without regard to technicalities or legal forms" (s 354(3) of the 1998 Act), and according to rules relating to its jurisdiction and function that are made by the Minister (s 364(1) of the 1998 Act). Fourth, that there is nothing inherently or exclusively judicial in the exercise of an adjudicative function (thus, the appellants say it is not determinative that the Commission's role is to adjudicate "disputes").
The appellants further contend that there are a number of "bespoke features" which tell against the Commission constituted by an Arbitrator being regarded as exercising judicial power, namely: that an Arbitrator is not required to be legally trained, but can have such qualifications as the Minister thinks fit (see s 369(3)(b) of the 1998 Act); that an Arbitrator (and the Commission generally) has an inquisitorial power, to obtain information of its own motion (s 357 of the 1998 Act) and is not bound by the rules of evidence but may inform itself "on any matter in such manner as the Commission thinks appropriate and as the proper consideration of the matter before the Commission permits" (s 354(2)); that an Arbitrator is required, before determining a dispute, to first use "the Arbitrator's best endeavours to bring the parties to the dispute to a settlement acceptable to all of them" (s 355(1) of the 1998 Act - i.e., to facilitate alternative dispute resolution before then hearing and determining a claim) and the parties are not permitted to make a bias application or any other objection based upon the Arbitrator's use of "best endeavours" to settle the dispute (s 355(2)); and that the rules of the Commission relating to its jurisdiction and function are made by the Minister (s 364(1) of the 1998 Act) and Arbitrators are subject to the "general control and direction of the Registrar" (s 372(2) of the 1998 Act).
The appellants thus argue that the Commission constituted by an Arbitrator is exercising a function which is "merely administrative"; namely, to arbitrate "disputes" that may arise when a person lodges a claim for compensation with an employer. The appellants say that, while this Court has previously seen no reason to doubt that "the Commission does exercise judicial powers" (citing Orellana-Fuentes v Standard Knitting Mills Pty Ltd (2003) 57 NSWLR 282; [2003] NSWCA 146 at [37]-[52], especially [39] per Ipp JA; Spigelman CJ and Handley JA agreeing) although it "is not a court", those remarks were not directed to the function of the Commission constituted by an Arbitrator, nor were they directed to the context of the present appeal.
Finally, while the appellants accept that a conclusion that Anshun does not apply may from time to time contribute to what Arbitrator Harris described in Miller (No 8) as the "inefficiency of the application of Commission resources" (see at [144]) the appellants contend that the existence of inefficiency in particular cases does not advance the question of statutory construction presented by the present appeal, because it is for the legislature to balance inefficiency against the interest in recovering compensation entitlements under a beneficial scheme of statutory compensation (and they maintain that the legislature has done so by the provisions of the 1987 Act and the 1998 Act referred to above).

Respondent's submissions

The respondent points to the appellant's acknowledgement that, if an Anshun defence as a matter of law is available in these proceedings, no appeal is maintainable; noting that the appeal is limited expressly to the appellant's proposition that the common law doctrine of Anshun estoppel cannot be applied in the determination of proceedings brought in the Workers Compensation Commission. That said, the respondent accepts that the context of the appeal is relevant, pointing (as have the appellants) to the history of the proceedings leading to the present appeal.
Referring to the decisions in Miller (No 1) and Miller (No 4), the respondent maintains that the different outcomes are impossible to reconcile except upon the basis that different but available inferences were drawn by different Arbitrators from much the same facts. The respondent says that there were two sets of proceedings both seeking the same benefit and resulting in contradictory judgments on the issue of whether "death results from injury".
The respondent accepts that the application of relevant principle to claims under Workers Compensation legislation has long been recognised to present difficulty, noting that the history of the application of Anshun estoppel in workers compensation proceedings was outlined in Israel v Catering Industries (NSW) Pty Ltd [2017] NSWWCCPD 53 (Israel v Catering Industries) at [107]-[127]. The respondent says that it is evident from the history there summarised that Anshun estoppel has consistently been applied in situations where the dispute concerned the whole issue of liability to pay compensation, a matter then was sought to be agitated in subsequent proceedings seeking the same compensation, and it was found to have been unreasonable not to have relied on that matter in the original proceedings. It is said that in each case care was taken to distinguish between successive claims where the dispute extended to the whole question of liability to pay compensation and successive claims where the issue was liability for disparate injuries suffered in the same but otherwise compensable incident.
The respondent argues that this approach is consistent with the Salmon Street decision and says that, insofar as the appellants contend that Salmon Street establishes that Anshun estoppel did not apply in the South Australian statutory regime, this is incorrect. The respondent says that King CJ was careful to distinguish between disputes which extended to the whole issue of liability to pay compensation and disputes where compensation was claimed for separate entitlements arising from the one incident. It is said that his Honour's conclusion was that these separate entitlements would not merge in a decision concerning a claim for one of those entitlements; but that a finding as to res judicata was appropriate where a determination was made in a dispute concerning the whole question of liability to pay. The respondent says that, with respect to Anshun estoppel, King CJ concluded that an application could be an abuse of process in a matter if a particular claim should have been included in the primary application.
The respondent notes that Salmon Street and other relevant authorities were reviewed by Neilson J in Bruce v Grocon Ltd (1995) 11 NSWCCR 247; [1995] NSWCC 10 (Grocon), where his Honour concluded that Anshun estoppel will apply to decisions in the Compensation Court if there were alternative bases to ground the relief claimed but one of those bases was not pursued. The respondent says that the Compensation Court and its successor, the Workers Compensation Commission, have consistently applied Anshun estoppel, limited in the way identified in Salmon Street, that is to disputes which "extend to the whole issue of liability to pay".
Having regard to the way that the Commission (and its predecessor, the Compensation Court) have accommodated the difficulties of importing common law doctrines into the operation of the statutory regime, the respondent maintains that the real issue for determination by this Court is whether Anshun estoppel is available as a defence to a claim for statutory entitlement when the issue in dispute is the "whole issue of liability to pay". It is submitted that, considered in this way, much of the appellants' argument can be seen to be focussed upon already acknowledged but accommodated difficulties when applying common law principles to the statutory scheme.
The respondent places weight on the decision of this Court in Lambidis v Commissioner of Police (1995) 37 NSWLR 320 (Lambidis), which concerned whether estoppel could operate so as to preclude the hearing of a matter in the Compensation Court on the basis there had been a prior determination by the Government and Related Employees Appeal Tribunal. It is noted that the appellant in Lambidis submitted that s 17 of the Compensation Courts Act 1984 (NSW) disclosed a legislative intention that the Compensation Court should not be bound by any form of estoppel arising from proceedings in some other tribunal and that the Court should examine any matter before it anew and on the merits. In that case, Priestley JA (with whom Kirby P, as his Honour then was, and Powell JA agreed on this point), noted (at 335) that "[f]or the appellant to succeed on this argument he would have to show that the effect of section 17 is to exonerate the Compensation Court from applying rules of substantive law or arriving at decisions according to legal criteria".
The respondent notes that s 17 provided, inter alia, that a decision of the Court in any matter should be determined "upon the real merits and justice of the case" and also provided that the Court should not be bound to follow strict legal precedent (similar to s 354(3) of the 1998 Act); and that this Court in Lambidis concluded that the Compensation Court was not exempt from an obligation to apply the rules of substantive law or from the obligation to arrive at decisions according to legal criteria. Kirby P there said (at 326) that: Substantially for the reasons given by Priestley JA, I would not read section 17 as excluding, by reference to 'the real merits and justice of the case' the ordinary principles of law that are applicable to the resolution of the issue in hand. Involved in considering 'the real merits and justice of the case is the obligation to accord proper respect for an earlier determination, by a body with relevant jurisdiction of an issue which concludes or properly should have concluded an issue later joined between the parties.
The respondent notes that the appellant properly concedes that s 354(3) does not exclude the application of the rules of substantive law and has referred to Lambidis as authority for this proposition but says that the appellant has not dealt with the substance of the decision nor with the reference by Kirby P to the availability of Anshun estoppel. The respondent points out that, after referring to the issue whether a tribunal's decision could give rise to an Anshun estoppel, Kirby P observed (at 325) that: Even if, contrary to my conclusion, determinations by tribunals, as such, could not give rise to issue estoppels because based on notions of pleading and the law of evidence inappropriate to a tribunal, such foundations would have no application to the operation of Anshun estoppels. Such estoppels are not so based. They depend upon considerations of public policy and the reasonableness of the conduct of litigants. Those considerations apply equally to tribunals such as [GREAT] as to courts. Accordingly, I see no reasons why they could not be invoked in the case of successive proceedings involving substantially the same issues before GREAT and before the Compensation Court.
Section 17(4) of the legislation there empowered the Court to reconsider any matter which had been dealt with by it and to rescind, alter or amend any decision previously made (akin to the effect of s 350(3) of the 1998 Act to which the appellants have referred and on which they rely). It is noted by the respondent that the existence of this provision was referred to but made no difference to the outcome in Lambidis. Further, it is said that authority in the Compensation Court limited its operation such that it would only be applied in "highly unusual circumstances where there is some manifest injustice to be remedied" and only after the need to rectify injustice had been balanced as against the finality of litigation.
In response to the ten arguments raised by the appellants in their submissions, the respondent says that the first, and the fourth to seventh, reasons focus on acknowledged difficulties in the application of common law principles to a statutory scheme such as the workers compensation scheme in New South Wales. The respondent says that those difficulties have been accommodated in the prior authority applying Anshun estoppel to which reference has already been made above. The respondent says that the repeated reference in the appellants' submissions to the claimed need for a principle such as Anshun estoppel to have general application to such a scheme elides the difference between disputes concerning disparate entitlements arising from the one otherwise compensable incident and disputes concerning the whole question of liability to pay.
With respect to the second reason, it is said that the appellants' submission does not sit comfortably with the concession made by the appellants that the application of the rules of substantive law have not been excluded and the decision of this Court in Lambidis that the relevant rules of substantive law continued to have application.
With respect to the third and eighth reasons, the respondent says that there is no need for such a statutory restriction or for the posited statutory power if the Anshun principle otherwise applies. As to the ninth reason, the respondent refers to its submissions on the outcome of Lambidis.
As to the tenth reason, the respondent says that it is wrong to conclude that an Arbitrator makes a mere administrative decision as distinct from exercising judicial power. The respondent says that the decisions made by an Arbitrator involve determinations as to fact and law, and involve the exercise of a discretion; and that, on current authority, in making those determinations, an Arbitrator is obliged to apply "the ordinary principles of law that are applicable to the resolution of the issue in hand". Insofar as the appellants refer to the absence of a power in the Commission to enforce its own determinations, the respondent notes that the Commission's predecessor (the Compensation Court) similarly did not have the power to enforce its own decisions. The respondent says that provision for the enforcement of awards and orders made by judges of the Compensation Court was to be found in s 23 of the relevant legislation (pursuant to which enforcement of the Court's decision was to be by the filing of a certificate in the District Court and then pursuant to enforcement procedures under the District Court Act 1973 (NSW)). Finally, the respondent says that the appellants' submissions (at 53) assume, incorrectly, that the ordinary principles of law are not applicable where the statute directs attention "to equity, good conscience and the substantial merits of the case".
The respondent thus submits that it is clearly wrong to conclude that the Arbitrator exercises a function which is "merely administrative". Further, the respondent says that (as the appellant concedes), the issue relevant to this appeal is whether Anshun estoppel is available noting the availability of estoppel is not "confined to an exercise of judicial power".

Appellants' submissions in reply

By way of clarification, the appellants note in their reply submissions that the historical version of the legislation which is relevant to the determination of this appeal is the version in force at the time of the deceased's death (being the reprint for 1 February 2011 to 30 June 2011) and that the definition to which the respondent refers at [7] of its submissions was introduced in 2012. The appellants note that, in the relevant version of the legislation, where the injury was characterised as the aggravation, acceleration, exacerbation or deterioration of a "disease", the employment had to be "a contributing factor", not (as the respondent suggests at [7]) "the main contributing factor".
Insofar as the respondent (at [3]-[15]) has summarised the "context of the appeal", the appellants say that this summary tends to overlook certain matters. First, that the injury the subject of the second application (anoxia and cardiac arrest) was a different injury from that which was the subject of the first application (an asthma attack). It is noted that Arbitrator Harris described it as "a different injury occurring at a slightly different time, some 30 minutes later" (see at [68]). The appellants emphasise that Arbitrator Harris' findings in that regard were not the subject of a presidential appeal and are not before this Court. Second, it is said that the suggestion that "different but available inferences were drawn by different arbitrators from much the same facts" seriously understates the significance to the conclusions drawn in Miller (No 4) of the additional evidence of Dr Jennings and Professor Fulde. It is noted that, in describing the additional evidence (from [47]) Arbitrator Wynyard emphasised (at [48]) that, whereas it had not been relevant to the first application, that evidence was relevant as the issue was now whether the deceased's anoxia and cardiac arrest arose out of or in the course of her employment (see at [49]) and that, in the dispositive part of the reasoning (see at [116]), Arbitrator Wynyard then specifically relied upon and "accept[ed]" the additional evidence in the course of reasoning to his conclusion. Third, it is said that the respondent's reference to "contradictory judgments" (at [15] of its submissions) is wrong at a terminological level (because the Commission does not give "judgments", instead, it gives "a certificate as to the determination", together with a "brief statement" setting out the Commission's reasons (ss 294(1)-(2) of the 1998 Act)) and over-stated at a substantive level (because the certificates (and reasons) resolved different claims based upon different injuries, based upon different evidence).
The appellants note the acknowledgment by the respondent that the application of Anshun under Workers Compensation legislation "has long been recognised to present difficulty" (see the respondent's submissions at [16]) and that the respondent appears not to dispute that some features of the statutory scheme are inconsistent with the importation of an "Anshun defence" (see submissions at [31]). As to the two related submissions advanced by the respondent in support of the application of Anshun in the Commission (first, that the difficulties "have been accommodated in the prior authority" (see at [31]); and, second, that this is done by distinguishing between "disputes concerning disparate entitlements arising from the one otherwise compensable incident and disputes concerning the whole question of liability to pay" (see at [32])), the appellants say the following.
As to prior authority, the appellants accept that the Commission has previously decided that Anshun applies under the statutory scheme but say that none of the decisions involved any analysis of the statutory features which the appellants here have raised for consideration. It is submitted that this Court has not previously considered the application of Anshun in the context of this statutory scheme, but the appellants maintain that the Full Court of South Australia has decided in Salmon Street that Anshun does not apply to a statutory scheme which the appellants submit (and say the respondent does not contradict) was relevantly analogous. To that extent, it is submitted that the "prior authority" is against the respondent.
As to the distinction drawn by the respondent between the "whole issue of liability to pay compensation" (for example at [17] of the respondent's written submissions) and "disparate injuries suffered in the same but otherwise compensable incident" (for example at [18] of those submissions), the appellants say that this appears to involve a concession that Anshun does not prevent an injured person from bringing separate claims in respect of "disparate injuries" (or perhaps for "disparate entitlements"), even though they may be suffered in the same incident; and that, if so, the distinction does not assist the respondent. It is said that the unchallenged finding in the Commission was that the first application (proceeding no 5831 of 2016) represented a "separate and distinct" (see at [154]) cause of action to the second application (proceeding no 2472 of 2019), precisely because the pleaded "injury" was different. It is said that the first injury (the asthma attack) was suffered 30 minutes before the second injury (the anoxia and cardiac arrest). Thus, the appellants say that, applying the respondent's terminology, the unappealed findings of the Commission require the conclusion that these claims arise from "disparate injuries suffered in the same but otherwise compensable incident".
It is submitted that, if the respondent's distinction depends upon a difference in the "entitlements", then the submission is directly inconsistent with Salmon Street. The Full Court held that the worker was "not required to raise in the proceedings all injuries or impairments which he has sustained in the accident or even all injuries or impairments of which he is then aware". The appellants say that there were thus two distinct claims, for the same statutory entitlement, at different times (claim for an injury to the head with conceptual loss of smell and taste, which was resolved by consent in 1984; and a claim in relation to the same injury resulting in vertigo); and therefore the respondent's position cannot be reconciled with Salmon Street (yet the respondent does not invite the Court to distinguish or depart from Salmon Street).
Insofar as the respondent contends that Anshun estoppel applies where what is determined is the "whole issue of liability to pay", the appellants say that this begs the question as to "liability for what"; and that the answer to that question must be liability under the 1987 and 1998 Acts to pay compensation. The appellants say that such an answer destroys the logical utility of the distinction because, under the statutory scheme, an employer is liable in respect of a claim based upon an injury. It is said that the language itself ("whole issue of liability to pay") seems to be taken from Salmon Street, but from a passage where King CJ was saying that disputes are sometimes merely about quantum, but at other times extend to "the whole issue of liability". The appellants say that this is no foundation for the posited distinction in the application of Anshun (that it merely recognised that employers sometimes admit liability but dispute quantification). Moreover, it is said that King CJ emphasised that, even where the dispute extended to "the whole issue of liability", any resemblance to a common law action "must not be allowed to obscure" that the jurisdiction of the Industrial Court is to "determine questions and disputes arising in the compensation process". The appellants say that neither Salmon Street nor any other case holds that Anshun turns upon the posited distinction between the "whole issue of liability to pay" and "disparate injuries suffered in the same but otherwise compensable incident".
Finally, the appellants say that the legislation does not support the respondent's distinction. It is submitted that there is no statutory foundation for a preclusionary principle applying only to certain classes of disputes, somehow involving the "whole issue of liability"; rather, the statutes recognise that there can be different liabilities to pay, for different injuries, and claims made at different times. The appellants emphasise that the jurisdiction of the Commission is attracted by "a dispute in connection with a claim for compensation" (s 287(1) of the 1998 Act), noting that a "claim for compensation" must include "full details" of the "injury" (s 282(1)(a)). It is submitted that there is nothing in the legislation which prevents different claims being advanced based upon different "injuries". There is no obligation to bring forward all "injuries" at the same time.
As to the emphasis placed by the respondent on the decision of this Court in Lambidis (see at [23]-[30]), the appellants say that the question of law for decision in Lambidis, as stated by Priestley JA, concerned res judicata and issue estoppel (not Anshun); and that the observations by Kirby P about Anshun were therefore obiter dicta. In any event, it is noted that his Honour said that Anshun was capable of arising in the case of a tribunal such as the tribunal there in question and that, in order to decide the scope and operation (inter alia) of Anshun estoppel, it was necessary to direct attention to precisely what it was that the tribunal was authorised to, and did, decide.
The appellants maintain that the legislative framework at issue in Lambidis was very different from that here being considered, noting that in Lambidis there were two statutory entitlements each depending upon an identical determination of the causality of a single injury: the first entitlement depending upon a determination that the "injury [was] received in the actual execution of the duty of his office" (from which an appeal lay to the tribunal against the decision of the Commissioner); and, the second entitlement depending upon a determination that "the infirmity" was "caused by the member being hurt on duty" (from which decision a person aggrieved by that decision could apply to the Compensation Court for a determination).
It is said that, in that context, no question of Anshun did or could arise because there was no ability for the police officer to agitate before the tribunal the decision (presumably not yet made) about his second (superannuation) entitlement, and that the finding of this Court was that the decision of the tribunal precluded (by an issue estoppel) the police officer from running the very same arguments rejected by the tribunal before the Compensation Court. The appellants say that there is no question about issue estoppel in this appeal.
As for the respondent's submissions concerning judicial power (see at [36]-[37] of its written submissions), the appellants say that the premise that an Arbitrator applies the law in the course of making determinations does not require a conclusion that the power is judicial in nature; and that the formation of an opinion as to legal rights and obligations can also be an incident of the exercise of administrative power. Second, in relation to the submission at 36, the appellants accept that it is not determinative that the Commission does not have the power to enforce its own determinations (referring to their submissions at 53). It is noted that the High Court has recently clarified that the nature of the order (here, a certificate) must be distinguished from the mechanism for enforcing that order. Nevertheless, the appellants say that it remains relevant, in characterising the nature of the power, that the purportedly "final and binding" nature of the Commission's decisions is expressly subject to the exceptions provided by the Act (see s 350(1) of the 1998 Act), and the Act provides that the Commission "may reconsider any matter that has been dealt with by the Commission and rescind, alter or amend any decision previously made or given by the Commission" (s 350(3)).

Determination

As is well understood, an Anshun estoppel "preclude[s] the assertion of a claim or of an issue of law or fact if the claim or issue was so connected to the subject matter of the first proceeding as to make it unreasonable, in the context of the first proceeding, for the claim or issue not to have been made or raised in it" (see Timbercorp Finance Pty Ltd (in liq) v Collins (2016) 259 CLR 212; [2016] HCA 44 at [27] (per French CJ, Kiefel, Keane and Nettle JJ)). It is an extension of "cause of action estoppel" (which operates to preclude assertion in a subsequent proceeding of a claim to a right or obligation which was asserted in the proceeding and which was determined by the judgment) and "issue estoppel" (which operates to preclude the raising in a subsequent proceeding of an ultimate issue of fact or law which was necessarily resolved as a step in reaching the determination made in the judgment).
The High Court in Tomlinson v Ramsey Food Processing (French CJ, Bell, Gageler and Keane JJ) said (at [22]): The third form of estoppel is now most often referred to as "Anshun estoppel", although it is still sometimes referred to as the "extended principle" in Henderson v Henderson. That third form of estoppel is an extension of the first and of the second. Estoppel in that extended form operates to preclude the assertion of a claim, or the raising of an issue of fact or law, if that claim or issue was so connected with the subject matter of the first proceeding as to have made it unreasonable in the context of that first proceeding for the claim not to have been made or the issue not to have been raised in that proceeding. The extended form has been treated in Australia as a "true estoppel" and not as a form of res judicata in the strict sense.
The reference to Anshun as a "true estoppel" may be understood as being a reference to an estoppel analogous to estoppel by deed or estoppel by representation (see Rogers v The Queen (1994) 181 CLR 251; [1994] HCA 42 where Deane and Gaudron JJ said (at 274-275) that issue estoppel was not a true estoppel - compare this with the dicta of Fullagar J in Jackson v Goldsmith (1950) 81 CLR 446; [1950] HCA 22 at 466) but was instead a different manifestation of the same policy considerations underpinning res judicata, namely: finality, injustice to an individual, and the "scandal of conflicting decisions". It is noted by the appellants that in Rogers v The Queen, Deane and Gaudron JJ said that the Anshun principle "if it be one, is to be treated with caution" and that it is "separate and distinct from the principles which secure the final, binding and conclusive nature of judicial determinations" (their Honours noting that the conflation of those principles could only result in confusion).
That Anshun has a distinct juridical foundation to issue estoppel and res judicata was affirmed in Chamberlain v Deputy Commissioner of Taxation (1988) 164 CLR 502; [1988] HCA 21 where it was said by Deane, Toohey and Gaudron JJ at 509, and Dawson J at 512 that Henderson v Henderson was not concerned with res judicata "in its strict sense".
The question here for determination, as noted above, is whether an Anshun estoppel may apply in relation to a statutory claim, namely, a claim brought in accordance with the 1987 Act.
Of relevance to the present matter is Salmon Street, to which both parties have referred. In that case, as noted earlier, the respondent had claimed weekly payments of compensation for work due to a head injury resulting in vertigo, there having previously been a determination by consent by the Industrial Court that the respondent receive a lump sum payment pursuant to s 69 of the Workers Compensation Act 1971 (SA) for the loss of the senses of smell and taste consequent upon the same injury. The appellant contended that the claim for weekly payment was barred as res judicata by virtue of the previous determination and that the institution of proceedings was therefore an abuse of process. There, the Court (King CJ, Cox and Bollen JJ agreeing) held that the claim for compensation for vertigo did not merge into the consent determination in the Industrial Court and was thus not statute barred. The determination under s 69 of the Workers Compensation Act did not, it was held, impair the right to weekly payments during incapacity resulting from vertigo, but only to incapacity resulting from loss of taste and smell. The Court held that only where a claim in respect of a particular injury or impairment is pleaded and is made the subject of a prior determination is a claim merged in the determination and barred as res judicata.
The relevant passages of the reasons of King CJ are as follows: Res judicata, or cause of action estoppel, arises where "the very right or cause of action claimed or put in suit has in the former proceedings passed into judgment, so that it is merged and has no longer an independent existence …": see Blair v Curran (1939) 62 CLR 464 at 532, per Dixon J; Port of Melbourne Authority v Anshun Pty Ltd (1981) 147 CLR 589 at 597, where a cause of action, having been litigated in a prior proceeding, has merged into judgment in that proceeding. It applies also, however, in an extended sense to matters which were not litigated in the prior proceeding but belonged properly to the subject matter of the prior proceeding and could have been raised in that proceeding: Port of Melbourne Authority v Anshun (supra) (at 598). … The application of these principles to claims under the Workers Compensation legislation presents difficulties. If the claim were a claim for damages at common law, the position would be clear. Where there is a judgment in an action for damages at common law for bodily injury resulting from a wrongful act, all claims for damages for bodily injury resulting from that act merge in the judgment and no action can subsequently be maintained for any further bodily injury subsequently discovered. … The rights to compensation under the Workers Compensation legislation, however, differ markedly in nature from the rights to damages for a wrongful act conferred by the common law and the means provided for enforcing claims for workers compensation are also very different from the common law remedies. The Workers Compensation Act does not create a single cause of action for compensation for injury sustained in a particular accident. A worker may under this Act, as was the case under the Commonwealth Employees' Compensation Act 1930 (Cth) which was considered in Commonwealth v Matheson (1955) 93 CLR 403, be compensable separately in respect of disparate injuries sustained in the same accident and may pursue separate claims in respect of such injuries. Thus where a worker sustained a leg injury and a back injury in the same accident, it was held that the receipt of a lump sum for the leg injury did not disentitle the worker to subsequent weekly payments in respect of the back injury: see Lee v Commonwealth (1971) 18 FLR 400.
King CJ went on to say that the "role of the Industrial Court is incompatible with the notion that, where a dispute is brought to the court as to liability for a particular injury, the worker is obliged to raise all other injuries arising out of the accident notwithstanding that they may not be in dispute at all". His Honour then said: In my opinion a worker who seeks to have a disputed right to compensation in respect of a particular injury determined in the Industrial Court is not required to raise in the proceedings all injuries or impairments which he has sustained in the accident or even all injuries or impairments of which he is aware. He may obtain an award in respect of one or more injuries or impairments, and subsequently pursue his claim in respect of other injuries or impairments suffered in the same accident. If, however, a claim in respect of a particular injury or impairment is pleaded in the proceedings and is the subject of a determination either granting compensation or dismissing the claim, the claim in respect of that injury or impairment merges in the determination and subsequent proceedings for the determination of a disputed claim in respect of the same injury or impairment would be barred as res judicata. It is therefore necessary to examine the pleadings in the prior proceedings and the terms of the award in order to determine whether the subsequent claim is barred.
As outlined above, the appellant submits that Salmon Street establishes that Anshun estoppel did not apply in the South Australian statutory regime. Whereas, the respondent submits, on the other hand, that King CJ was careful to distinguish between disputes which extended to the whole issue of liability to pay compensation and disputes where compensation was claimed for separate entitlements arising from the one incident. The respondent submits that King CJ concluded that these separate entitlements would not merge in a decision concerning a claim for one of those entitlements. However, a finding as to res judicata was appropriate where a determination was made in a dispute concerning the whole question of liability to pay. The respondent further submits that, with respect to Anshun estoppel, King CJ concluded that an application could be an abuse of process in a matter if a particular claim should have been included in the primary application.
Salmon Street was applied in Stephenson v Return to Work Corporation of South Australia (2019) 134 SASR 141; [2019] SASCFC 89 (Stephenson). At issue in that case was whether an order by consent that a worker had no further or other entitlement pursuant to s 43 of the Workers Rehabilitation and Compensation Act 1986 (SA) made at a conciliation conference released and discharged the compensating authority from liability from entitlements claimed subsequently for injuries that had not yet arisen, and founded an estoppel in respect of that claim. A Full Bench of the South Australian Employment Tribunal held that such an order did release and discharge the Corporation, and founded an Anshun estoppel which precluded the claim of the appellant. On appeal to the Full Court of the Supreme Court of South Australia, the appellant submitted that the Tribunal could not make an order precluding all entitlements for injuries not yet suffered and which may develop in the future. Kourakis CJ (with whom Nicholson and Parker JJ agreed) allowed the appeal, holding that the order made by consent did not found a cause of action estoppel.
Salmon Street was also followed by Moroney J in Kerr v Hunter District Water Board (1991) 7 NSWCCR 289 (Kerr). In that case, a worker had obtained lump sum compensation under s 66 of the 1987 Act sufficient to entitle him to an award under s 67 of that Act. The worker only made his claim for lump sum compensation under s 67 in the subsequent proceedings. Moroney J held that no estoppel arose in that regard. His Honour determined that the Compensation Court does not create a single cause of action in respect of all claims for compensation arising out of injuries sustained in a particular accident. His Honour went on to say that a worker is not required to raise in proceedings before the Compensation Court all injuries sustained in an accident or even all injuries or impairments of which the worker is aware. Each of Stephenson and Kerr is consistent with the submissions of the respondent as to the delineation between issues as to whole of liability, and circumstances in which further injuries arise from the same accident.
In Grocon, to which reference has also been made above, Neilson J, sitting in the Compensation Court of New South Wales, considered the application of Anshun estoppel in the context of the 1987 Act. In that case, a worker suffered a compensable injury, and underwent consequential surgery and physiotherapy. The worker claimed lump sum payments under the Act, but did not include a claim for weekly payments of compensation. By consent, the Compensation Court entered an award for the lump sum payments. The worker then claimed weekly payments of compensation. The employer submitted that the worker was estopped from claiming weekly payments for the period of the first award. The Compensation Court held that there was persuasive authority for the proposition that there is no "cause of action" for workers compensation, and that the Act creates a number of rights which a worker is entitled to pursue independently of other rights (here citing Salmon Street and Thompson v George Western Foods Ltd (1990) 6 NSWCCR 370 (Thompson v George Western Foods)). The Court further held that estoppel will arise if the relief claimed in the second or subsequent proceedings was claimed in the original proceedings, again citing Salmon Street and that, furthermore, Anshun estoppel will apply if there were alternative bases to ground the relief claimed, but one of those bases was not pursued.
Neilson J went on to cite a number of cases where the application of Anshun estoppel was considered in the context of the 1987 Act. First, his Honour considered Ada v Westmead Centre Parramatta Hospital (1985) 1 NSWCCR 101, in which Burke J held that a worker was estopped in accordance with the principles of Anshun estoppel. The worker in that case alleged incapacity due to injury to his arm with consequential or associated anxiety disorder. In earlier proceedings, the worker had alleged that the incapacity in question arose from his having fallen from a chair and striking his head upon a wall. In the proceedings before Burke J, the applicant alleged that the incapacity resulted from repetitive movements and the strenuous use of his injured arm. In disposing of the matter, Burke J said the following (at 106): It seems to me where the subject of the earlier litigation was whether the applicant had an incapacity because of the injury to his left arm and a consequent anxiety state and that was alleged to be compensable because it arose out of or in the course of his employment and the applicant alleged one only of apparently two limbs or incidents of his employment upon which he might rely, then certainly it was in essence the applicant splitting his case seeking in two separate proceedings ultimately to allege two different causes of the same consequence, each being allegedly compensable within the meaning of this Act. It seems to me that with any reasonable diligence the applicant could have, and indeed should have, litigated that issue concurrently with the actual allegation which he did in fact choose to litigate in the earlier proceedings.
Neilson J also considered Thompson v George Western Foods, cited above, which involved an application for a review of a decision of a Commissioner, the main ground of challenge being that it was made without jurisdiction. In that case, McGrath CJ said the following: It is clear that issue estoppel can arise as a consequence of an adjudication on a particular issue, which would prevent a party bringing, or defending, a claim in relation to a different benefit. I do not consider that there is any rule which would prevent a worker bringing an action claiming one type of benefit, and leaving another type of benefit for later, or other, adjudication. In doing this he may in some cases risk being penalised in costs, or risk failing on an issue which would debar the other claim. If he lost on the issue of injury he could not succeed in gaining compensation for a consequential benefit, whether it was included in the original application or not.
In Israel v Catering Industries, cited above, the Workers Compensation Commission was called upon to determine whether a claim for s 66 entitlements in respect of a consequential lower back condition should have been brought with an earlier claim for a lower back injury both arising from the same injury. In that case, the applicant appealed from the decision of the Commission where the Arbitrator found in favour of the respondent in respect of Ms Israel's claim for a lump sum entitlement. The Arbitrator determined that Ms Israel was estopped from bringing a claim pursuant to s 66 in respect of the lumbar spine. The lumbar symptoms were said to be a consequence of her altered gait from her knee injury. At [196] the Commission held that an Anshun estoppel can apply in a claim for workers compensation.
In Lambidis, Kirby P (as his Honour then was) considered the application of Anshun estoppel to preclude an appeal to the Compensation Court. The question posed to the Court in Lambidis was: If not res judicata or issue estoppel, after the decision of the Government and Related Employees Appeal Tribunal, was the appellant otherwise precluded from pursuing the appeal to the Compensation Court by [Anshun] which prevents a party from later relying upon a claim or defence which it has unreasonably refrained from raising in earlier proceedings which were so closely connected with the later subject matter that it might reasonably have been expected that the claim or defence would have been raised?
In answering this question, Kirby P (as his Honour then was) quoted his judgment in O'Brien v Tanning Research Laboratories Inc (1988) 14 NSWLR 601 (at 325) wherein his Honour stated:
… With the development of arbitration and of administrative tribunals, both of which enjoy significant standing and follow procedures akin to those used in the courts, there would appear to be no reasons of principle why, at least in cases such as the present, estoppel should not arise to prevent the needless re-opening or unwarranted re-agitation of matters formally concluded by an appropriate tribunal, according to law. …
His Honour held that there was no reason why Anshun estoppel could not be invoked in the case of successive proceedings involving substantially the same issues before the Government and Related Employees Appeal Tribunal and before the Compensation Court. In reaching this conclusion, his Honour reasoned as follows: Substantially for the reasons given by Priestley JA, I would not read section 17 [which provided that a decision of the Compensation Court should be determined upon the real merits and justice of the case, without regard to technicalities or legal forms] as excluding, by reference to the real merits and justice of the case, the ordinary principles of law that are applicable to the resolution of the issue in hand. Involved in considering the real merits and justice of the case is the obligation to accord proper respect to an earlier determination, by a body with relevant jurisdiction, of an issue which concludes or properly should have concluded, an issue later joined between the parties.
In Southern Tablelands Health Service v Solomon (1999) 19 NSWCCR 235, Walker J again considered the application of Anshun to workers compensation claims. In that case, the worker suffered injury to her neck and leg, brought proceedings in relation to those injuries, and subsequently settled those proceedings. The worker then brought a claim in relation to an arm injury, which resulted from the same accident as the neck and leg injuries. Walker J held at [26] that an Anshun estoppel may be available in the context of the 1987 Act, dependant on the reasonableness of the party's omission to raise a claim or defence in the earlier proceedings.
Finally, I note that in Coshott v Barry [2015] NSWCA 257, which concerned a statutory claim under the Bankruptcy Act 1966 (Cth), the Court said in discussing whether an Anshun estoppel can apply to a statutory claim, at [96]: In light of our conclusion on the bankruptcy issue, it is unnecessary to determine the estoppel issue. However, we would note in this context that despite the many arguments that the Solicitors advanced on this point, prima facie, the estoppel argument would not run, on the basis that there cannot be an estoppel in the face of a statute. Although the parties referred to this proposition, neither fully argued it. The question whether a statute has the effect of precluding an estoppel must turn on a consideration of the relevant legislation. Having regard to the purposes of the Bankruptcy Act as explained above, in particular, in ensuring the rateable distribution of the bankrupt's assets amongst all creditors and precluding individual creditors acting on their own initiative, we would be of the view that there can be no estoppel in the face of that statute.
This, however, does not preclude an Anshun estoppel in relation to a statutory claim, provided that it is in keeping with the purpose of the particular Act.
In the present matter, the appellants submitted that the legislative framework of the 1987 Act and the 1998 Act is not consistent with the application of Anshun estoppel for the ten reasons set out above. Of particular relevance is the appellants' submission that there is no provision of the statutory framework which authorises the disqualification of a statutory entitlement by the operation of a non-statutory common law defence. In particular, the appellants submit that the importation of Anshun estoppel into the scheme of the legislation (the 1987 Act and the 1998 Act) is inconsistent with s 9 of the 1987 Act, which provides that the dependants of a deceased worker "shall receive compensation from the worker's employer in accordance with this Act". Further, as noted above, the appellants rely on s 261(3) of the 1998 Act, which contemplates that multiple claims for compensation may be made at different times in respect of the injury or death concerned. The reasons put forward by the appellants focus on difficulties in relation to the application of common law principles to a statutory scheme, which the respondent acknowledges. They elide, however, the authorities applying Anshun estoppel in this context, which accommodate those difficulties.
Section 9 of the 1987 Act provides as follows: 9 Liability of employers for injuries received by workers - general (cf former s 7 (1) (a)) (1) A worker who has received an injury (and, in the case of the death of the worker, his or her dependants) shall receive compensation from the worker's employer in accordance with this Act. (2) Compensation is payable whether the injury was received by the worker at or away from the worker's place of employment.
The reliance by the appellants on s 9(1) of the 1987 Act and the absence of any provision in the Act which authorises the disqualification of a statutory entitlement by the operation of a non-statutory common law defence, in order to submit that the legislative scheme in the 1987 Act creates a code for compensation entitlements to the exclusion of common law principles, is misinformed. Indeed, the appellants conceded that the substantive law has not been excluded by the Act. In any event, the decision of this Court in Lambidis provides that the relevant rules of the substantive law have continued application, and in the absence of any provision to the contrary in the legislative scheme, that decision ought to be followed. Section 9 of the 1987 Act is not inconsistent with the continued application of Anshun estoppel within the context of that Act.
Relevantly, s 261 of the 1998 Act provides as follows: 261 Time within which claim for compensation must be made (1) Compensation cannot be recovered unless a claim for the compensation has been made within 6 months after the injury or accident happened or, in the case of death, within 6 months after the date of death. (2) If a claim for compensation was made by an injured worker within the period required by this section, this section does not apply to a claim for compensation in respect of the death of the worker resulting from the injury to which the worker's claim related. (3) For the purposes of this section, a person is considered to have made a claim for compensation when the person makes any claim for compensation in respect of the injury or death concerned, even if the person's claim did not relate to the particular compensation in question. …
The appellants rely on s 261(3) to demonstrate the incompatibility of the legislative scheme of the 1998 Act with the principle of Anshun estoppel, insofar as Anshun requires parties to bring forward their whole case, yet s 261(3) contemplates that multiple claims for compensation may be made at different times in respect of the injury or death concerned. While it may be accepted that there exists some tension between the principle of Anshun estoppel and s 261(3), this does not in my opinion engender wholesale inconsistency. This is so in light of the consistent application of Anshun in situations where the dispute concerns the whole issue of liability to pay compensation; where a matter has been agitated in subsequent proceedings in circumstances where it was unreasonable not to have relied on that matter in the original proceedings. Section 261(3) is not inconsistent with the operation of Anshun to preclude the agitation in subsequent proceedings of a matter relevant to liability to pay compensation. Rather, s 261(3) appears to me to contemplate circumstances in which successive claims are made concerning liability for disparate injuries suffered in the same, but otherwise compensable incident. There is not, therefore, any substantive inconsistency between the operation of s 261(3) and the continued application of Anshun within the context of the legislative framework beyond the acknowledged difficulties in the application of common law principles to a statutory scheme of this nature.
Those acknowledged difficulties also arise with respect to s 261(1), extracted above, which requires that claims for permanent impairment compensation in respect of an injury must, as far as practicable, be made at the same time. As noted above, the appellants contend that no such provision would be required if Anshun was of general application, and, further, that the phrase "as far as practicable" is inconsistent with the application of Anshun. However, this again elides the distinction between questions of whole of liability to pay compensation, and successive claims concerning liability for disparate injuries suffered in the same incident. I consider that, while the provision presents difficulties, it does not give rise to express inconsistency between the application of Anshun and the terms of the statute. This same analysis is applicable to ss 65(6), 65(9), and 66(2A) of the 1998 Act, which are in similar terms to the provisions extracted above
I am of the opinion that the provision against double recovery in the 1987 Act (see s 9AC(1)) is not inconsistent with the application of Anshun, insofar as Anshun only operates to preclude the re-agitation of questions of whole of liability to pay. So too with Pt 3, Div 8 of the 1987 Act, which makes provision for what is to occur in the event that a worker is successful in different claims under the Act at different times.
As to the appellants' submission that the application of Anshun is inconsistent with s 354(1) of the 1998 Act, with respect I consider that this submission is misconceived. Section 354(1) provided, at the relevant time, that: 354 Procedure before Commission (1) Proceedings in any matter before the Commission are to be conducted with as little formality and technicality as the proper consideration of the matter permits.
This provision does not, to my mind, present any inconsistency with the application of Anshun. This is so for two reasons. First, the Court considered a cognate provision in Lambidis, being s 17 of the Compensation Courts Act 1984 (NSW), which provided that any matter was to be determined upon "the real merits and justice of the case". There, the Court held that s 17 did not exclude, through reference to the "real merits and justice of the case" the ordinary principles of law applicable to the resolution of the issue in hand in that matter. That is also the case here. Second, the reference to "formality and technicality" cannot include Anshun within its scope - Anshun estoppel is neither a formality, nor a technicality, but a principle of law of fundamental importance which bears squarely upon the rule of law and issues of fairness and justice. There is thus no fundamental inconsistency between s 354(1) and the application of Anshun.
Finally, as to the appellants' submissions regarding the exercise of non-judicial power by the Commission, I do not consider it necessary to determine the nature of the power so exercised. The High Court in Tomlinson v Ramsey Food Processing clearly stated (at [21]) that: Estoppel in relation to judicial determinations is of a different nature. It is a common law doctrine informed, in its relevant application, by … considerations of finality and fairness. Yet its operation is not confined to an exercise of judicial power; it also operates in the context of a final judgment having been rendered in other adversarial proceedings. It operates in such a context as estoppel operates in other contexts: as a rule of law, to preclude the assertion of a right or obligation or the raising of an issue of fact or law. [footnotes omitted]
By s 350(1) of the 1998 Act, a decision of the Commission under the Workers Compensation Acts is final and binding on the parties (albeit subject to the abovementioned exceptions). The adversarial nature of proceedings before the Commission, and the finality of decisions resolving such proceedings, is sufficient to engage the principle of Anshun estoppel. It is therefore unnecessary to characterise the nature of the power exercised by the Commission in so doing.
It is to be borne in mind that one cannot expect there necessarily to be a perfect alignment between a statutory framework and common law principles. The relevant caselaw is replete with references to the acknowledged difficulty in applying common law principles such as Anshun to statutory frameworks such as these. Mere difficulty in the application of such principles should not, however, preclude any attempts to reconcile the two in the absence of an express exclusion of common law principles by the legislature, or manifest inconsistency between the statute and those principles. No such exclusion or inconsistency exists here.
In light of the foregoing, there is no reason in principle why Anshun estoppel ought not be applicable to the legislative schemes established by the 1987 and 1998 Acts.
I also agree with the observations of Brereton JA at [136]. For the above reasons, I propose that the appeal be dismissed with costs.
BRERETON JA: On 15 April 2011, while driving a community bus from Brewarrina to Dubbo in the course of her employment with the respondent Department of Communities and Justice, the late Ms Moori Miller suffered an asthma attack which, after around 30 minutes, caused anoxia and cardio-pulmonary arrest, ultimately leading to her death. On 10 November 2016, the deceased's husband the first appellant David Miller applied to the then Workers Compensation Commission (now the Workers Compensation Division of the Personal Injury Commission) for compensation, based on the "injury" which caused her death being the asthma attack; the deceased's dependant son the second appellant Terren Tuhi was joined as a respondent. This application was dismissed, on the ground that the deceased's employment was not a "substantial contributing factor" to that "injury", [1] because she had suffered from asthma for all of her life, and it was not in dispute that the driving of the bus on 15 April 2011 did not bring on the ultimately fatal asthma attack. [2] Appeals to a Deputy President, [3] and then to this Court, [4] were unsuccessful.
On 22 May 2019, the appellants made a further application for compensation, this time identifying the "injury" as the ultimate anoxia and cardiac arrest. An arbitrator accepted that the relevant "injury" was cardio-pulmonary arrest and found that that injury was causally connected to the deceased's employment, as the remote location in which she was required to work deprived her of prompt access to the kind of treatment for her asthma attack that would have averted the cardio-pulmonary arrest and death. The arbitrator also rejected arguments that the appellants were estopped from bringing the new claim, essentially because the pleaded injury was different, so that there was no inconsistency with the earlier determination. [5] On appeal, the arbitrator's conclusions as to injury and causation were not disturbed, but Phillips PICP held that the arbitrator had erred in consideration of the issue estoppel and Anshun [6] estoppel issues, and remitted the matter to a different arbitrator. [7] Following clarification that the remitter was confined to the questions of issue estoppel and Anshun estoppel, [8] another arbitrator did not accept that the appellants were barred by an issue estoppel (on the basis that the second claim was "for a different injury occurring at a slightly different time, some 30 minutes later"), but found that an Anshun estoppel was established, concluding that it was unreasonable that the appellants had not relied on anoxia and cardiac arrest as relevant injuries in the first application. [9] On 23 September 2021, Snell DP confirmed the arbitrator's decision. [10]
The appellants' appeal to this Court from the determination of a Deputy President of the Workers Compensation Commission is confined to a point of law. [11] The sole ground of appeal is that: "The Deputy President erred in point of law in holding that Anshun estoppel was available to defeat the [appellants'] claim in circumstances where the Commission had found that the deceased has died in the course of her employment with the respondent and that her employment was a substantial contributing factor to the injury that resulted in her death."
The single point of law raised in this appeal is whether the doctrine of "Anshun" estoppel is applicable to proceedings to recover statutory entitlements to compensation under the 1987 Act and the 1998 Act. It was expressed on behalf of the appellants in the following terms: "Is the application of the common law doctrine of estoppel associated with Port of Melbourne Authority v Anshun Pty Ltd (1981) 147 CLR 589 as a defence to statutory entitlements consistent with the scheme of the Workers Compensation Act 1987 (NSW) (1987 Act) and the Workplace Injury Management and Workers Compensation Act 1998 (NSW) (1998 Act)?"
The factual background, including the history of the litigation, the legislative framework, and the competing submissions of the parties, are set out comprehensively in the judgment to be delivered by Ward P, which I have had the benefit of reading. I agree with her Honour that the appeal fails, for the reasons given by her Honour, but I wish to add some further remarks as to why in my opinion the Anshun doctrine is applicable to proceedings for compensation under the 1987 and 1998 Acts.
The Anshun doctrine precludes a party from asserting in later proceedings a claim which, having regard to all the circumstances, could and ought reasonably have been brought in earlier proceedings. It is engaged only where the party has unreasonably failed to assert a right or defence in connection with or in the context of the earlier proceeding. [12] The rationale of the Anshun doctrine is to prevent a party being vexed by multiple proceedings when the issue raised in the later proceedings ought reasonably have been raised in the earlier proceedings. Proceedings which are caught by Anshun are ex hypothesi vexatious. The Commission had power, under (former) s 354(7A), [13] to dismiss proceedings that are vexatious. Contrary to the respondent's submissions, the existence of that power is consistent, rather than inconsistent, with the application of Anshun, because it embraces dismissal on the grounds which would attract Anshun.
Further, the application of Anshun in the compensation jurisdiction, albeit in a somewhat circumscribed way, is well-established by authority. [14] The application of Anshun in this context must have regard to the legislative structure and scheme, and also to conventions of practice and procedure, because such conventions inform a judgment as to whether it is unreasonable in the circumstances not to have brought a particular claim earlier. But that is not to say that the doctrine does not apply; only that whether a claim ought reasonably have been brought in the context of an earlier claim will be informed by those matters. To the extent that the legislative scheme does not permit one claim to be litigated in the context of another, the Anshun doctrine would not be engaged. Similarly, if as a matter of practice in the jurisdiction, it was usual for one type of claim to be brought separately and later than another, Anshun would not require that it be brought in earlier proceedings. What the authorities establish is that a worker is not required to bring forward at once all claims for all types of compensation in respect of all injuries arising out of the one event, and may pursue different types of compensation and in respect of different injuries separately, but may not in a later application claim, on an alternative basis, the same relief as has earlier been denied - which is what the appellants here sought to do.
For those reasons, and the reasons given by the President, the appeal fails on the merits. However, the error alleged in the sole ground of appeal was not made expressly, because at no earlier stage had the point been taken. Until the appeal to this Court, the case had been conducted on the basis that Anshun was available in law, but not engaged on the facts. If the point was to be taken, it should at least have been raised on the appeal to Phillips PICP. It is unreasonable to raise it now only after remitter, rehearing, and a further appeal to Snell DP. Had it been raised earlier, the respondent might have invoked s 354(7A), which authorised dismissal of proceedings on the ground that they are vexatious, as an alternative basis for substantially the same outcome. The loss of the ability to do so is prejudicial to the respondents.
I agree with the orders proposed by the President.
MITCHELMORE JA: I agree with Ward P.

Endnotes

Within the meaning of s 9A(1) of the Workers Compensation Act 1987 (NSW) ("the 1987 Act").
Miller v The State of New South Wales [2017] NSWWCC 66 ("Miller No 1").
Miller v State of New South Wales [2017] NSWWCCPD 38 ("Miller No 2").
Miller v State of New South Wales [2018] NSWCA 152 ("Miller No 3").
Miller v Secretary, Department of Communities and Justice (No 2472/19, 11/10/19) ("Miller No 4").
See Port of Melbourne Authority v Anshun Pty Ltd (1981) 147 CLR 589; [1981] HCA 45.
Secretary, Department of Communities and Justice v Miller [2020] NSWWCCPD 38 ("Miller No 5").
Miller v Secretary, Department of Communities and Justice (No 2472/10, 1/7/2020) ("Miller No 6"); Secretary, Department of Communities and Justice v Miller [2020] NSWWCCPD 57 ("Miller No 7").
Miller and Tuhi v Secretary, Department of Family and Community Services [2021] NSWWCC 22 ("Miller No 8").
Miller v Secretary, Department of Communities and Justice (No 9) [2021] NSWPICPD 29 ("Miller No 9").
Workplace Injury Management and Workers Compensation Act 1998 (NSW) ("the 1998 Act"), s 353(1).
Timbercorp Finance Pty Ltd (in liq) v Collins (2016) 259 CLR 212; [2016] HCA 44 at [27] (French CJ, Kiefel, Keane and Nettle JJ); Tomlinson v Ramsey Food Processing (2015) 256 CLR 507; [2015] HCA 28 at [22] (French CJ, Bell, Gageler and Keane JJ).
See now Personal Injury Commission Act 2020 (NSW), s 54.
Ada v Westmead Centre Parramatta Hospital (1985) 1 NSWCCR 101; Thompson v George Western Foods Ltd (1990) 6 NSWCCR 370; Salmon Street Ltd (in liq) v Jorgensen (1991) 56 SASR 158; Kerr v Hunter District Water Board (1991) 7 NSWCCR 289; Lambidis v Commissioner of Police (1995) 37 NSWLR 320; Bruce v Grocon Ltd [1995] NSWCC 10; (1995) 11 NSWCCR 247; Southern Tablelands Health Service v Solomon (1999) 19 NSWCCR 235; Israel v Catering Industries (NSW) Pty Ltd [2017] NSWWCCPD 53 at [107]-[127]. 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: 23 September 2022

Compensation Courts Act 1984(NSW)

Workers Compensation Act 1971(SA)

Workers Rehabilitation and Compensation Act 1986(SA)

Workmen's Compensation Act 1971(SA)

Employees' Compensation Act 1930(Cth)

(1995) 11 NSWCCR 247

(1999) 19 NSWCCR 235

At a glance

Court

Decision date

Before

Catchwords

Source

Catchwords

Judgment (15 paragraphs)

Parties

Legislation Cited (10)

Cases Cited (43)