Amaca Pty Limited (Under NSW Administered Winding Up) v Roseanne Cleary as the Legal Personal Representative of the Estate of the Late Fortunato

Background

1. Mr Gatt was born on 17 February 1943. Between 5 June 1962 and 15 July 1964, he was employed by Amaca as a labourer at its factory in Camellia. During his employment, Mr Gatt was exposed to, and inhaled, asbestos dust and fibre. The primary judge found that Mr Gatt operated a "mixer machine mixing raw asbestos with other wet materials", he worked a minimum of 56 hours per week, that there were vast amounts of asbestos dust and fibre in the air, and he was regularly covered in asbestos dust from "head to toe". [2] The primary judge found that other employees who had worked at the Camellia plant at around the same time were exposed to very high levels of asbestos fibre which led to some of them developing asbestosis and other asbestos related medical conditions. Her Honour also found that "[s]ubstantial amounts of amphibole asbestos was likely to have been used". [3]
2. Mr Gatt commenced smoking in 1960 at age 17. He smoked up to 25 cigarettes a day at an average of 15 to 20 cigarettes per day. [4] He continued smoking until 2007 when he had a heart attack. [5] The primary judge found that he smoked at least 20 cigarettes a day from "about 1960 until about 2007" which constituted a "cumulative smoking history [in] the range of 47-70 pack years" where one "pack year" constitutes the consumption of 1 packet of 20 cigarettes each day of a year. [6]

The Issues and the Primary Judge's Findings

1. On 4 August 2020, the Respondent filed a Third Amended Statement of Claim. It was pleaded that the injuries suffered by Mr Gatt as a result of Amaca's negligence included lung cancer, asbestosis, and diffuse pleural thickening. In its defence, Amaca admitted that it owed and breached a duty of care to Mr Gatt. It admitted that Mr Gatt developed asbestos related pleural plaques but did not admit that he suffered the other pleaded injuries. Amaca also pleaded that Mr Gatt was contributorily negligent essentially because of his smoking.
2. Ultimately, the parties agreed on an amount for damages of $540,000 which included a discount for contributory negligence of 10%. [7] The primary judge identified the "issues" in dispute as: [8] "(i) On the balance of probabilities, did Mr Gatt suffer from asbestosis; (ii) What was the cumulative airborne asbestos concentration to which Mr Gatt was, on the balance of probabilities, exposed to during the period of his work at James Hardie; and (iii) Examination of the epidemiology of lung cancer and the causal [nexus] between asbestos exposure, cigarette smoke and the occurrence of lung cancer."
3. The parties accepted that this statement of the issues was meant to reflect the two alternative bases upon which the Respondent put her case on causation, namely, that (i) Mr Gatt had asbestosis which, if established, resulted from his exposure to asbestos at Amaca's factory; and that (ii) Mr Gatt's exposure to asbestos at Amaca's factory caused him to contract lung cancer without him having necessarily developed asbestosis. If either were established then it was accepted that the Respondent could recover the agreed damages. With the second limb there were two sub-issues, namely, what level of cumulative airborne asbestos concentration was Mr Gatt exposed to during his employment by Amaca and, depending on that level of exposure, whether it was established that that exposure was a cause of his lung cancer. Amaca denied both limbs of the Respondent's case and pointed to Mr Gatt's heavy smoking history as the cause of his lung cancer.
4. As noted, ultimately, her Honour made findings favourable to the Respondent in respect of both limbs of her case. [9] In relation to the level of cumulative airborne asbestos concentration, the primary judge found that Mr Gatt was exposed to at least 24.4 fibres/ml.years; that is, he was exposed to the equivalent of 1 asbestos fibre per cubic centimetre, per day, for 24.4 years. [10]
5. On appeal, Amaca accepted that to succeed it had to demonstrate error in relation to the primary judge's findings on both limbs of the Respondents' case, although they did not challenge her Honour's findings concerning Mr Gatt's level of cumulative airborne asbestos exposure. The respective parties' case and her Honour's reasons are best explained in the context of Amaca's challenge to each of those findings.

Finding of Asbestosis: Appeal Grounds 1(a) and 2

1. Grounds 1(a) and 2 of Amaca's Amended Notice of Appeal challenge her Honour's finding that the late Mr Gatt developed asbestosis. Those grounds contend: "1. The primary judge erred in law in not accepting evidence adduced by the appellant, being: (a) the unchallenged evidence of Dr Jones, Dr Goldin, Dr Baldey, Dr Carr and A/Prof McKenzie on the issue of whether Mr Gatt suffered from asbestosis; and (b) … in circumstances where none of these witnesses was cross-examined and their evidence was contrary to the evidence adduced by the plaintiff in relation to [this issue] (Judgment at [247]-[255]; [261]-[264]). 2. The primary judge erred in law in failing to infer that the evidence of Dr Snodgrass would not have assisted the plaintiff's case on the issue of whether Mr Gatt suffered from asbestosis, in circumstances where the plaintiff failed to call Dr Snodgrass and called no evidence to explain that failure (Judgment at [90])."

The Respective Parties' Cases on Asbestosis

1. The Respondent called evidence from Dr James Leigh, a consultant occupational physician, who has undertaken extensive research into asbestos related diseases over many years, and Dr Anthony Johnson, a respiratory and sleep physician. Dr Leigh's evidence was principally directed to the epidemiology of asbestos exposure, smoking and lung cancer. However, in his report dated 31 December 2018, he noted that the "extensive bilateral calcified pleural plaques [observed on Mr Gatt's lungs] are objective evidence of significant cumulative asbestos exposure." A report of a CT (computed tomography) scan of Mr Gatt's chest, undertaken on or around 15 October 2015 (the "October 2015 Scan"), when Mr Gatt was diagnosed with lung cancer, showed "[l]arge calcified pleural plaques" on his lungs. The primary judge found that that scan was significant because it was taken "prior to the progression of Mr Gatt's lung cancer and treatment related changes." [11]
2. In one of his reports, Dr Johnson referred to the October 2015 Scan and to high resolution CT scans of Mr Gatt's chest in September 2003 (the "September 2003 Scan") which showed "bilateral calcified pleural plaques" and "increased interstitial markings sub pleurally in both lower lobes." Dr Johnson concluded as follows: "In my opinion it is more likely than not Mr Gatt contracted asbestosis and ARPD [Asbestos Related Pleural Disease] due to his asbestos exposure whilst employed by James Hardie. This is based on the radiological features consistent with a diagnosis of asbestos related pleural disease and interstitial pulmonary fibrosis. There was no other obvious cause for his interstitial pulmonary fibrosis apart from his asbestos exposure. His asbestos exposure was sufficiently heavy to have caused asbestosis. Therefore my diagnoses are asbestosis and asbestos related pleural disease i.e. pleural plaques and diffuse pleural thickening."
3. On the issue of whether Mr Gatt had contracted asbestosis, Amaca adduced evidence from four specialist radiologists, Dr Michael Jones, Dr Graeme Goldin, Dr Andrew Baldey and Dr Peter Carr, and a respiratory physician, Associate Professor McKenzie.
4. The primary judge summarised Dr Jones' evidence in some detail. [12] The effect of all three of his reports was that the October 2015 Scan did "not confirm asbestosis or any other interstitial lung disease" [13] and that a finding of asbestosis could not be made based on that scan. [14] Dr Jones' final report dated 11 October 2020 was responsive to Dr Johnson's final report. In that report, Dr Jones concluded that "the late Mr Gatt did not have asbestosis". To similar effect, Dr Goldin reviewed various scans and concluded that "there are lung parenchymal changes associated with the pleural plaques but these are not the diffuse changes of typical asbestosis."

The Primary Judge's Reasoning on Asbestosis

1. Under the heading "diagnosis of asbestosis", the primary judge summarised the evidence of the expert witnesses just noted. [16] Her Honour then noted a submission by Amaca that "as the [Respondent] did not cross-examine Dr Jones, Dr Carr or A/Prof McKenzie … the plaintiff thus cannot advance a case which contradicts their evidence" citing the "rule" in Browne v Dunn (1893) 6 R 67 ("Browne v Dunn") as discussed in Ghosh v Medical Council of New South Wales (2020) 102 NSWLR 303; [2020] NSWCA 122 ("Ghosh"). [17]
2. Her Honour accepted the Respondent's submission that in this case her Honour was "not required to form a view as to the specialists' integrity" and was not "at an advantage or disadvantage by the presence of one witness in the witness box and the other views being expressed entirely in written form." [18] Her Honour referred to the second "aspect" of the "rule" identified by Brereton JA in Ghosh which is concerned with the weight to be afforded to such evidence that is not the subject of cross‑examination. Her Honour observed: [19] "I accept that the second part of the rule [in Browne v Dunn] does not require me to accept the uncross-examined evidence. So far as the second limb is concerned, all that the rule requires me to do is to weigh in the balance of probabilities the absence of cross-examination, which I have done."
3. Her Honour then referred (again) to the evidence of Dr Jones and Dr Johnson before noting that an issue had arisen with the Respondent's proposal to call evidence from Dr Snodgrass, a radiologist who had either supervised or at least seen the September 2003 Scan. Her Honour noted that Dr Snodgrass had been served with a subpoena to give evidence although: [20] "88 It became clear to me, by statements from the Bar table that Dr Snodgrass was a reluctant witness, despite my offer to sit outside court hours at his convenience, and also to take his evidence by AVL or telephone. 89 Thus, the plaintiff was unable to call Dr Snodgrass to give evidence, and his report was removed from the plaintiff's tender bundle. 90 The defendant submits that as no explanation was offered, that I should infer that Dr Snodgrass' evidence would not have assisted the plaintiff's case: Jones v Dunkel (1959) 101 CLR 298, and that as a consequence I would more readily resolve the question in favour of the defendant. 91 I do not accept that the failure to call Dr Snodgrass to give evidence should cause me to infer that his evidence would not have assisted the plaintiff's case. It is clear to me that the plaintiff tried to get him to attend, but he refused to do so. I cannot see that there was anything else the plaintiff could have done and as such I have had no regard to Dr Snodgrass' opinion."

Ground 1(a) - Browne v Dunn: Submissions

1. Ground 1(a) is set out above. Amaca's submissions in support of this ground focussed on the so-called "rule" in Browne v Dunn and Brereton JA's discussion of that rule in Ghosh. The principal complaint made in writing was that the primary judge did not disclose what impact the failure to cross‑examine had on the weight that was attached to the evidence of the experts relied on by the Respondent. Hence, it was contended that the finding of the primary judge as set out at [25] above does not specify why, notwithstanding the lack of cross-examination of Dr Jones, his evidence was flawed and should not be accepted. It was submitted that her Honour appears to have treated the lack of cross‑examination of Dr Jones and the other experts relied on by Amaca as telling against an acceptance of those witnesses when Ghosh suggests that the position should be to the contrary.
2. Amaca contended that her Honour did not explain how Dr Johnson's examination of Mr Gatt in 2018 "made him better placed to" interpret the October 2015 Scan than the experts relied on by Amaca. While it was accepted that it was not expressly put to Dr Johnson that the films did not demonstrate "interstitial fibrosis", Amaca contended that the issue was raised with him and the reliance on the absence of something being put to Dr Johnson only highlighted the flawed approach that was taken to Amaca's witnesses. It was also submitted that error was somehow demonstrated by the failure of the primary judge to refer to the evidence of Dr Goldin, Dr Baldey and Dr Carr in the discussion section of her Honour's reasons.
3. The Respondent's written submissions contended that, given the manner in which Dr Johnson was cross‑examined on behalf of Amaca, it was not necessary for her to cross‑examine Dr Jones or Dr Carr. The submissions also contended that the reports of Dr Goldin and Dr Baldey did not state whether or not Mr Gatt had asbestosis or interstitial fibrosis, so that presumably no obligation arose on the Respondent to cross‑examine them on that issue. It was submitted that, to the extent that the "rule" in Browne v Dunn might require the acceptance of evidence, it was only if that evidence was "uncontradicted" whereas the evidence the subject of this ground of appeal was contradicted. During the hearing of the appeal, Senior Counsel for the Respondent, Mr Walker, contended that all of Amaca's complaints in relation to this limb of the Respondent's case only raised questions of fact and not points of law for the purposes of s 32(1) of the Dust Diseases Tribunal Act 1989 (NSW) (the "DDT Act"). For the reasons stated next, that submission should be accepted.

Ground 1(a) - Browne v Dunn: Determination

1. As noted, these appeals are governed by s 32(1) of the DDT Act which relevantly provides that "[a] party who is dissatisfied with a decision of the Tribunal in point of law or on a question as to the admission or rejection of evidence may appeal to the Supreme Court". This right of appeal is not confined to a case where the Tribunal has made a decision on a point of law. Instead, an appeal lies where a party is dissatisfied in point of law with a decision of the Tribunal; i.e. the scope of the appeal is synonymous with the existence of an error of law (see Seltsam Pty Ltd v Ghaleb [2005] NSWCA 208 at [149]; Amaca Pty Ltd (under NSW administered winding up) v Raines; Seltsam Pty Ltd v Raines [2018] NSWCA 216 at [12] to [17]).
2. Long‑standing authority in this Court, namely Azzopardi v Tasman UEB Industries Ltd (1985) 4 NSWLR 139 ("Azzopardi"), demonstrates the significant limitations on the review by this Court of findings of primary fact by an inferior court where the appeal is restricted to demonstrating an error of law. Hence, in Azzopardi (at 155 to 156) Glass JA observed that: "It is clear ... that numerous pejorative expressions in common usage possess a single meaning and are interchangeable. To say of a finding that it is perverse, that it is contrary to the overwhelming weight of the evidence, that it is against the evidence and the weight of the evidence, that it ignores the probative force of the evidence which is all one way or that no reasonable person could have made it, is to say the same thing in different ways. Upon proof that the finding of a jury is vitiated in this way, it will be set aside because it is wrong in fact. Since the Act does not allow this Court to correct errors of fact, any argument that the finding of a Workers' Compensation Commission judge is vitiated in the same way discloses no error of law and will not constitute a valid ground of appeal. It is also pointless to submit that the reasoning by which the court arrived at a finding of fact was demonstrably unsound as this would not amount to an error of law: R v District Court of the Metropolitan District Holden at Sydney; Ex parte White (1966) 116 CLR 644 at 654. A finding of fact in the Commission may nevertheless reveal an error of law where it appears that the trial judge has misdirected himself ie has defined otherwise than in accordance with law the question of fact which he has to answer. A possibility of this kind exists with ultimate findings of fact but not with respect to primary findings of fact such as whether the applicant suffered injury on a particular date. Further an ultimate finding of fact, even in the absence of a misdirection, may reveal error of law if the primary facts found are necessarily within or outside a statutory description and a contrary decision has been made, Hope v Bathurst City Council (1980) 144 CLR 1 at 10; Australian Gas Light Co v Valuer-General (1940) 40 SR (NSW) 126 at 138; 57 WN 53 at 55. The decision here assailed is not of that character."

Unpleaded Complaint of Denial of Procedural Fairness

1. Amaca's written submissions in support of ground 1(a) noted that, during the hearing before the primary judge, it sought to call Dr Jones "with the intention of assisting the Court by asking Dr Jones to explain the images reproduced in his reports." The submissions contended that, following objection by the Respondent, "the primary judge advised that she did not need such assistance and declined to allow Dr Jones to be called". Amaca contends that this was an "indication" by the primary judge that her Honour "fully understood and accepted the evidence of Dr Jones". This is said to be a "circumstance relevant to whether the primary judge erred in law, and denied the appellant procedural fairness, in accepting the evidence of Dr Johnson over that of Dr Jones and the rest of the body of evidence to the same effect."
2. The complaint of a denial of procedural fairness was not raised as a ground of appeal. In any event, it has no substance. During the hearing before the primary judge, Senior Counsel for Amaca sought to lead oral evidence from Dr Jones about the images to show "why Dr Johnson is wrong". He added that if "there is simply no challenge to Dr Jones, his evidence is taken to be accepted, then I do not need to call him". Senior Counsel for the Respondent opposed the application on the basis that he was "content with what Dr Jones says in his report". He said he had not "secured radiological evidence to contradict Dr Jones" and had determined not to cross‑examine him. He added that if "Dr Jones is now going to lead some additional evidence, there should be a report and I will have to determine whether or not in light of that whether I have to find additional radiological evidence". Her Honour stated that she agreed.
3. After further submissions the following exchange occurred: "HER HONOUR: … I do not think it is fair to now bring Dr Jones along to adduce some additional evidence, it should be done appropriately by a report and then the plaintiff is entitled to an opportunity to consider that report and they may change their case. [SENIOR COUNSEL FOR AMACA]: It has been done by report, your Honour. That is the point I was making. All I was seeking to do with him, your Honour, was to have him show you what he has done in his report. HER HONOUR: I do not need that assistance, thank you."
4. I do not consider that these exchanges constitute any "indication" by her Honour that she "fully understood and accepted" Dr Jones' evidence. Her Honour's statement that she did not need assistance was directed to whether her Honour needed assistance in understanding Dr Jones' report. It did not constitute any statement that his evidence would be accepted. Nothing that occurred in this exchange means that the findings her Honour made in relation to Dr Jones involved any denial of procedural fairness.

Ground 2: Jones v Dunkel

1. Ground 2 of the Amended Notice of Appeal contends that her Honour erred in law in failing to draw an inference that Dr Snodgrass would not have assisted the Respondent's case on the issue of whether Mr Gatt suffered asbestosis. Dr Snodgrass had viewed the September 2003 Scan. During the hearing of the appeal, the suggested inference that it is submitted her Honour should have drawn was refined to an inference that Dr Snodgrass "would not have given evidence that supported the plaintiff's case in terms of the presence on the imaging of signs of early asbestosis".
2. The reasons of the primary judge in relation to this issue are set out above. Amaca's submissions in this Court contend that there was no evidence to support her Honour's assessment that Dr Snodgrass had "refused to attend" and that her Honour's refusal to draw the inference sought was erroneous in law.
3. This ground is misconceived. Jones v Dunkel (1959) 101 CLR 298; [1989] HCA 8 ("Jones v Dunkel") is authority for the proposition that two possible consequences may follow from a party's failure to call a witness whom they might be expected to call. The first is that the Court may infer that the evidence of the witness who was not called would not have assisted that party's case (a "Jones v Dunkel inference"). The other consequence is that the Court may have greater confidence in drawing an inference unfavourable to that party (Jones v Dunkel at 308 per Kitto J; Kuhl v Zurich Financial Services Australia Ltd (2011) 243 CLR 361; [2011] HCA 11 at [63] to [64]; ASIC v Hellicar (2012) 247 CLR 345; [2012] HCA 17 at [232] per Heydon J; "Hellicar"). This latter consequence can be put aside as no inference unfavourable to the Respondent was contended for by Amaca in this case.
4. A Jones v Dunkel inference has relatively weak evidentiary value. It does not enable the trier of fact to infer that the absent evidence would have been positively adverse to the party (Hellicar at [168] per French CJ, Gummow, Hayne, Crennan, Kiefel and Bell JJ and at [232] per Heydon J), and it does not enable a court to discount or diminish the value of the evidence that a party adduced (Hellicar at [164] to [170] and [233]). In this case, a Jones v Dunkel inference was irrelevant to both the Respondent's case and her Honour's reasoning, because both relied on Dr Johnson's evidence and that evidence could not be diminished by any failure to call Dr Snodgrass (Hellicar supra). Otherwise, the inference is only available where the party could be expected to call a witness who was in their "camp" (Hellicar at [265]). It is doubtful that a specialist such as a doctor who viewed a scan in September 2003 could be properly described as being in the Respondent's camp.

Epidemiology of Lung Cancer: Appeal Grounds 1(b) and 3 to 5

1. As noted, one part of the Respondent's case sought to establish a causal link between Mr Gatt's exposure to asbestos and his development of lung cancer (without finding that he contracted asbestosis). The primary judge ultimately upheld that part of the Respondent's case. [25] Grounds 1(b) and 3 to 5 of the appeal attack that aspect of her Honour's reasons. They contend: "1 The primary judge erred in law in not accepting evidence adduced by the appellant, being: (a) … (b) the unchallenged evidence of Prof Moolgavkar, A/Prof Chirieac, Dr Gal, A/Prof McKenzie and Prof Fox on the issue of epidemiology of lung cancer … in circumstances where none of these witnesses [were] cross-examined and their evidence was contrary to the evidence adduced by the plaintiff in relation to these two issues (Judgment at [247]-[255]; [261]-[264]). ... 3 The primary judge erred in law in applying the wrong test for causation because the primary judge conflated the epidemiological concept of relative risk of development of lung cancer with proof, on the balance of probabilities, of causation of lung cancer (Judgment at [198]-[199], [214]-[215], [262]). 4 The primary judge erred in law by failing to apply, as a minimum threshold, the issue of a general nature determined in a previous proceeding before the Dust Diseases Tribunal of NSW; that issue being that the relative risk of contracting lung cancer in consequence of working with asbestos cement building materials in Australia between 1955 and 1980 doubled at 50 fibres/ml.years of cumulative exposure (Judd v Amaca Pty Limited [2003] NSWDDT 12 at [44]), which matter was set out in a notice pursuant to s 25B of the [DDT Act] (Judgment at [203]). 5 The primary judge erred in law in failing to address a substantial and clearly articulated case advanced by the appellant that the causal potency of the historical asbestos exposure was significantly diminished by the passage of approximately 50 years between the last exposure to asbestos and the diagnosis of lung cancer, with the result that the relative risk from asbestos exposure was little, if any, greater than 1."
2. To address these grounds, it is first necessary to describe the epidemiological evidence that was adduced by the parties and her Honour's reasoning.

The Respondent's Epidemiological Evidence

1. The Respondent also relied on evidence from Dr Leigh and Dr Johnson on this limb of her causation case. The essence of Dr Leigh's evidence was that it is not possible to separate the causal effects of asbestos exposure and cigarette smoking "when both have acted, as they must do to some extent, from a purely physio-chemical point of view, and it is thus more probable than not, that in this situation, the lung cancer was the singular result of the two factors acting together". [26]
2. There was a significant debate amongst the parties, which was reflected in the primary judge's reasons, as to whether Dr Leigh's evidence in this case was the same as that described in Amaca Pty Ltd v Ellis (2010) 240 CLR 111; [2010] HCA 5 ("Ellis") (at [33]) and which was held not to have supported a finding of causation in that case (at [65]). It is not necessary to consider this further as the primary judge did not base her finding on this limb of the Respondent's causation case on Dr Leigh's evidence. However, it will be necessary to return to Ellis in addressing how the primary judge addressed evidence called by Amaca from Professor Moolgavkar which was responsive to Dr Leigh's evidence.
3. As noted, Dr Johnson diagnosed Mr Gatt with asbestosis. In addition, he concluded: "There has been controversy about whether asbestos exposure without asbestosis causes lung cancer. The Helsinki criteria was a consensus published by a group of experts to address this situation in 1997 … and updated in 2014 ... Their conclusion was that asbestos exposure sufficient to have caused asbestosis i.e. 25 f/mlyr was sufficient to cause lung cancer in the absence of asbestosis. As I consider your client has asbestosis he does not need to fulfil the exposure criteria listed above. In any case based on an occupational hygienist expert assessment he does i.e. his exposure was likely to have been more than 25 f/mlyr. ... Both cigarette smoking and asbestos exposure are known to cause lung cancer. Based on the reasons above I consider his asbestos exposure alone sufficient to have caused his lung cancer. …Assuming Mr [Gatt] was exposed to 25 f/ml*yr in my opinion it is more likely than not [that] his exposure to asbestos dust at James Hardie was a material contributing cause of his lung cancer."

Amaca's Epidemiological Evidence

1. Five of the experts relied on by Amaca addressed whether there was a causal connection between Mr Gatt's exposure to asbestos and his contracting lung cancer in the absence of any diagnosis of asbestosis, being Associate Professor Chirieac, Dr Gal, Professor Fox, Professor Moolgavkar and Associate Professor McKenzie. None of these experts were cross‑examined.
2. Lucian Chirieac is an Associate Professor of Pathology at Harvard Medical School. He opined that "to attribute a substantial contributing role for asbestos in the causation of lung cancer, asbestosis must be present clinically or histologically, or there should be a tissue asbestos burden within the range of values observed in patients with asbestosis". He concluded that "[i]n the absence of clinical, physiologic, pathologic, or radiographic evidence of asbestosis, and in the presence of a long history of smoking, it is highly likely that Mr. Gatt's lung squamous cell carcinoma was related to a substantial tobacco use, and not caused by asbestos exposure."
3. Dr Gal is a specialist pathologist. In his report he referred to a debate as to whether or not "inhaled asbestos can only be considered to have caused an individual's lung cancer if asbestosis is also present in that individual". Dr Gal noted a recent paper that expressed the view that it was unlikely that "epidemiology alone can put either the strict scientific or practical medicolegal questions beyond doubt". He concluded "that the carcinoma can be shown to be primary to the lung by the clinical exclusion of other possible primary sites, then any history of significant tobacco smoking, would make that smoking the likely cause of Mr Gatt's pulmonary squamous cell carcinoma".
4. Professor Richard Fox is an Honorary Consultant to the Department of Clinical Haematology and Medical Oncology at the Royal Melbourne Hospital. In his report, Professor Fox referred to a series of research papers indicating that the "the risk of developing lung cancer following asbestos exposure diminishes with time after cessation of asbestos exposure". He noted that the information in those studies "has never been included in updates of the so called "Helsinki Criteria" which were developed in the 1990s based on data from the 1960s through to the 1980s". He concluded that the information derived from those studies was "significant" and that "given the passage of time following last asbestos exposure and Mr Gatt's lung cancer, [his] past asbestos exposure had a de [minimis] effect on causation of lung cancer compared with his smoking history."

Professor Moolgavkar's Evidence

1. In light of the primary judge's reasons, it is necessary to describe the reports of Professor Moolgavkar that Amaca tendered in some detail.
2. Professor Moolgavkar is a physician with a PhD in mathematics and post-doctoral training in pharmacology, biophysics, epidemiology and biostatistics. In his first report dated 10 October 2019, he recounts that he was asked to provide a report addressing, inter alia, the "risk of contracting a squamous cell carcinoma of the lung associated with the smoking history identified for Mr. Gatt" and the "cumulative exposure to the relevant asbestos [fibre] type necessary to double the risk of contracting carcinoma of the lung." His report addressed the epidemiology of lung cancer. He noted that: age is a strong factor for the development of lung cancer; the vast majority of lung cancers are caused by cigarette smoking; and that a recent study "confirms that very high levels of exposure to asbestos are required to increase, even modestly, the risk of lung cancer". Based on various studies, he observed that "compared to cigarette smoking, asbestos is a weak lung carcinogen, with exposure to several hundred [fibre millions/cubic centimetre years] being required to double the risk", that "amphibole asbestos is considerably more potent as a lung carcinogen than chrysotile asbestos" and that "[t]here is strong evidence that the risk of lung cancer following asbestos exposure is strongly modified by age".
3. In relation to the interaction between cigarette smoking and asbestos in lung carcinogenesis, Professor Moolgavkar noted that "[t]he Relative Risk [("RR")] for joint exposure to asbestos and smoking is generally taken to be multiplicative … although there is some evidence to suggest that it may be less than multiplicative but greater than additive". RR is the ratio of the probability of an outcome in an exposed group to the probability of an outcome in an unexposed group. Professor Moolgavkar said that it followed that "the assumption of a multiplicative RR puts an upper bound on the risk of lung cancer among smokers who are exposed to asbestos" and for "joint exposure to cigarette smoking and asbestos, an upper bound on the RR is given by a model that is an additive function of cumulative asbestos exposure and multiplies the RR for cigarette smoking."
4. One part of Professor Moolgavkar's first report is entitled "framework for attribution of risk of cancer to specific exposures". In this section, he described the concept of an "attributable fraction" (AF) in epidemiology, which he said has "often been interpreted as the probability that the disease in a diseased individual was caused by the exposure, and an attributable fraction of 0.5 or above, which corresponds to a RR of 2 or more, has been interpreted to mean that it was more likely than not that the exposure caused the disease." All of these passages are directed to an assessment of the risk or probability that a particular factor was causative.

Associate Professor McKenzie

1. As noted, Associate Professor McKenzie did not accept that Mr Gatt had asbestosis. However, he accepted that '[a]sbetos exposure has been reported to increase the risk of developing lung carcinoma" and described the Helsinki Criteria as "recognis[ing] epidemiological literature which indicated that individuals with a history of heavy exposure to asbestos had an increased risk of developing lung carcinoma, even if they did not have asbestosis." He noted that "[t]he Helsinki Criteria determined the level of exposure to amphibole asbestos which would be sufficient to double the risk of developing carcinoma of the lung, ie, would equate to a probability of causation of 50%."
2. Associate Professor McKenzie's report records that he undertook a similar process of assessing the risk attributable to smoking and asbestos to that undertaken by Professor Moolgavkar. Associate Professor McKenzie assumed a RR for cigarette exposure of 20, a RR for asbestos exposure of 1.2 and a "background risk" of 4.5%. He divided the "combined asbestos-smoking component of the risk" between the two causes with the contribution of smoking being 94.5% and asbestos being 1.0%. Based on those calculations he concluded "on the balance of probabilities, that the carcinoma in Mr Gatt's case was on the basis of cigarette smoking".

Primary Judge's Reasons on Epidemiology

1. The primary judge's reasons in relation to this limb of Mr Gatt's causation case addressed in detail the evidence and submissions concerning the cumulative level of asbestos exposure. [27] Her Honour then addressed the authorities in relation to causation and the epidemiology of lung cancer, including Ellis and Amaca v Booth (2011) 246 CLR 36; [2011] HCA 53 ("Booth"). Her Honour placed particular emphasis on the proposition accepted in Strong v Woolworths (2012) 246 CLR 182; [2012] HCA 5 at [26] that "[n]egligent conduct that materially contributes to the plaintiff's harm but which cannot be shown to have been a necessary condition of its occurrence may, in accordance with established principles, be accepted as establishing factual causation". [28] Her Honour then described aspects of Dr Leigh's evidence and the debate about whether his reasoning on causation was precluded by Ellis. [29] Her Honour then summarised some aspects of the other experts' reports, including that of Professor Moolgavkar. Her Honour noted Professor Moolgavkar's conclusion that "asbestos exposure made no contribution to the development of Mr Gatt's lung cancer" and observed: [30] "The conclusion that the asbestos made no contribution to Mr Gatt's cancer is not explained to the extent that I would accept that proposition. The vast majority of the opinions expressed in the report relate to 'risk'. To then opine as to the 'cause' of the disease, is not explained and not consistent with the balance of the report. Prof Moolgavkar concedes that 96% of the cancer is attributable to cigarette smoking. In my view, it is therefore reasonable to accept that the remaining 4% on Prof Moolgavkar's assessment, was caused by his asbestos exposure, given the defendant concedes that Mr Gatt was in fact exposed to asbestos dust and fibre at Camellia." (emphasis added)
2. Her Honour then returned to the first limb of the Respondent's causation case before reaching the conclusion above that Mr Gatt had asbestosis. Her Honour then returned to the second limb, reasoning as follows: "260 The Helsinki Criteria of 25 fibre/mL.years has also been referred to by the experts. As this was a figure at which there was for [some time] a consensus as to the bottom limit of cumulative exposure, it strengthens my view that the JER upper figure of 24.4, Prof McKenzie's figures of 10-20 fibres/mL.years and Dr Johnson's assessment of more than 25 fibres/mL.years, that Mr Gatt was more probably than not exposed to an airborne concentration of at least 24.4 fibres/mL.years. 261 Thus, I find that it is more probable than not that Mr Gatt's exposure to asbestos dust and fibre was a cause of Mr Gatt's lung cancer. I find that one substance (asbestos dust) which has been accepted by the parties as capable of causing lung cancer, did cause the injury and that Mr Gatt's cancer was intimately connected with, and contributed to by his exposure to asbestos. Having found that there is a connection between Mr Gatt inhaling asbestos and his development of lung cancer, I find that the inhalation of the asbestos dust and fibre made a material contribution to his development of lung cancer on the scientific evidence as I find that the fibre burden was sufficient to cause asbestosis. 262 I accept Prof Moolgavkar's view that lung cancer can be attributed to his cigarette smoking. Prof Moolgavkar apportions >96% to it. However, implicit in that statement, must be that there is some other carcinogen present to account for the other 4%, and I find on the balance of probabilities, that that was Mr Gatt's inhalation of asbestos dust which materially contributed to his lung cancer. 263 I find that the evidence establishes that the asbestos exposure did contribute to the cancer in the sense that it was a necessary precondition to it, and that contribution was material. 264 I find that the plaintiff has established on the balance of probabilities that Mr Gatt was exposed to sufficient asbestos dust and fibre in his employment with the defendant and as such dust and fibre materially contributed to his lung cancer." (emphasis added)

Ground 1(b): Failure to Cross-Examine

1. Ground 1(b) makes the same point as ground 1(a) except that it is directed to the epidemiological experts whose reports were relied on by Amaca. This ground fails for the reasons noted above in relation to ground 1(a).

Ground 3: Test for Causation

1. Ground 3 of the further Amended Notice of Appeal is set out above. The ground cross references various paragraphs of the primary judgment. Of those paragraphs, [215] and [262] of her Honour's reasons are set out above. Paragraph [214] of the primary judgment set out extracts from Professor Moolgavkar's reports that confirm that he was opining on the "risk" of asbestos exposure and smoking causing lung cancer. Paragraphs [198] to [199] contain a description and analysis of Professor Moolgavkar's evidence that is not materially different to that set out by her Honour in [215] and [263].
2. With respect to her Honour, these passages of the primary judgment misapprehend Professor Moolgavkar's evidence and the concept of "material contribution" as used in causation in the law of negligence.
3. To establish a cause of action in negligence, a plaintiff must prove on the balance of probabilities that the defendant's wrong caused or materially contributed to his or her loss. It is not sufficient for the plaintiff to show that the wrong only materially increased the risk of harm where medical science does not permit any further proof (Evans v Queanbeyan City Council [2011] NSWCA 230 at [20]-[23] per Allsop P, as his Honour then was, at [56] per Hodgson JA, and [93] and [103] per Basten JA, citing Ellis and Tabet v Gett (2010) 240 CLR 537; [2010] HCA 12). The concept and context of a material contribution were explained by Gummow, Hayne and Crennan JJ in Booth at [70] as follows: "The 'but for' criterion of causation proved to be troublesome in various situations in which multiple acts or events led to the plaintiff's injury, for example, where the development of a particular medical condition was the result of multiple conjunctive causal factors. In such cases what may be unclear is the extent to which one of these conjunctive causal factors contributed to that state of affairs. These situations have been addressed by the proposition stated by Lord Watson in Wakelin v London & South Western Railway Co [(1886) 12 App Cas 41 at [47]] that it is sufficient that the plaintiff prove that the negligence of the defendant 'caused or materially contributed to the injury".
4. Their Honours then referred to the discussion of Bonnington Castings Ltd v Wardlaw [1956] AC 613 ("Bonnington Castings") in Ellis. That discussion is of particular significance at this point. Like this case, Ellis concerned a smoker who had been exposed to asbestos and who later developed lung cancer. In Ellis, the Court described the effect of epidemiological evidence that was very similar to that set out above. This evidence utilised attributable fractions which "expressed the probability that the cancer in question was caused by exposure to the carcinogen or carcinogens in question" (at [24]). Although, in Ellis, various figures were attributed to the percentage likelihood that lung cancer was caused by asbestos, that figure was not greater than 23% and was always much less than that assigned to smoking being not less than 67% (at [30]). Of these figures, their Honours observed (at [64] to [65]): "If the relative risks and probabilities derived from epidemiological studies were to be treated as revealing what was a probable explanation of what caused Mr Cotton's cancer, those analyses support two conclusions. First, it is more probable than not that smoking was a cause of (in the sense that it was a necessary condition for) Mr Cotton's cancer. Second, the risks and probabilities associated with asbestos, whether alone or in conjunction with smoking, are low and not sufficient to found the inference which the plaintiff sought to have made: that it is more probable than not that exposure to respirable asbestos fibres was a cause of Mr Cotton's cancer. It was not shown to be more probable than not that asbestos was a cause of (a necessary condition for) his cancer. It was not shown that exposure to asbestos made a material contribution to his cancer. Material contribution was not shown because a connection between Mr Cotton's inhaling asbestos and his developing cancer was not demonstrated."

Ground 4: Section 25B Notices

1. Section 25B of the DDT Act provides: "25B General issues already determined (1) Issues of a general nature determined in proceedings before the Tribunal (including proceedings on an appeal from the Tribunal) may not be relitigated or reargued in other proceedings before the Tribunal without the leave of the Tribunal, whether or not the proceedings are between the same parties. (1A) If an issue of a general nature already determined in proceedings before the Tribunal (the earlier proceedings) is the subject of other proceedings before the Tribunal (the later proceedings) and that issue is determined in the later proceedings on the basis of the determination of the issue in the earlier proceedings, the judgment of the Tribunal in the later proceedings must identify the issue and must identify that it is an issue of a general nature determined as referred to in this section. (2) In deciding whether to grant leave for the purposes of subsection (1), the Tribunal is to have regard to: (a) the availability of new evidence (whether or not previously available), and (b) the manner in which the other proceedings referred to in that subsection were conducted, and (c) such other matters as the Tribunal considers to be relevant. (3) The rules may provide that subsection (1) does not apply in specified kinds of proceedings or in specified circumstances or (without limitation) in relation to specified kinds of issues. (4) This section does not affect any other law relating to matters of which judicial notice can be taken or about which proof is not required." (emphasis in original)
2. In the proceedings before the primary judge, each of the parties served a notice identifying an issue of a general nature that they contended had been determined in previous proceedings by the Tribunal. The Respondent referred to McDonald v State Rail Authority (1998) 16 NSWCCR 695; [1998] NSWDDT 4 at [72] ("McDonald") as demonstrating that "carcinoma of the lung may be attributed to asbestos exposure in the absence of asbestosis where the exposure was sufficient to have caused asbestosis". Amaca's notice referred to Judd v Amaca Pty Ltd (2003) 25 NSWCCR 125; [2003] NSWDDT 12 ("Judd") at [44] where Curtis DCJ concluded that "that the relative risk of contracting lung cancer in consequence of working with asbestos cement building materials in Australia between 1955 and 1980 doubled at 50 fibre ml years of cumulative exposure."

Ground 5: Risk of Lung Cancer from Asbestos Exposure Diminishes with Time

1. Ground 5 of the Amended Notice of Appeal contends that the primary judge erred in law in failing to "address a substantial and clearly articulated case" that the causal potency of Mr Gatt's exposure to asbestos diminished over time such that the "relative risk from asbestos exposure was little, if any, greater than 1."
2. The use of the phrase "substantial and clearly articulated" in the formulation of this ground suggests that Amaca seeks to rely upon the statement in Dranichnikov v Minister for Immigration and Multicultural Affairs (2003) 77 ALJR 1088; [2003] HCA 26 ("Dranichnikov") at [24] that "[t]o fail to respond to a substantial, clearly articulated argument relying upon established facts was at least to fail to accord ... natural justice". However, nothing in Amaca's written submissions sought to invoke Dranichnikov or the cases that have followed it.
3. In any event, this ground can be disposed of shortly. The proposition that the causal potency of exposure to asbestos diminishes over time vis a vis lung cancer was "clearly articulated" by Professor Moolgavkar. It was incorporated into his estimates of the RR for asbestos that he used in the calculations set out above. However, the primary judge utilised Professor Moolgavkar's figure of 96% which was derived using a RR for asbestos of 1.03. This figure reflected Professor Moolgavkar's opinion that the causal potency of the exposure reduced over time. Hence, the foundation for this ground of appeal is not made out. The fact that her Honour misunderstood and misapplied Professor Moolgavkar's calculation using that figure is a different point and the basis for ground 3 which I have upheld.
4. I would reject ground 5.

Other Matters

1. Some aspects of Amaca's submissions do not match its grounds of appeal. For example, Amaca contended that the "primary judge further erred in relying on the Helsinki Criteria" in [260] of the judgment because her Honour disregarded the evidence from the Respondent's witnesses that was critical of its use. The Helsinki Criteria and some of the expert's evidence about it are referred to above. Similarly, the submissions complain that the primary judge did not refer to the evidence of Dr Gal and Professor Fox in the "discussion" section of her Honour's reasons (although it was summarised elsewhere).
2. Consistent with the discussion of Azzopardi (and Soulemezis) noted above, these complaints do not raise any error, point or question of law.

Ground 6: Failure to Find a Fact

1. Ground 6 of the Amended Notice of Appeal provides: "In the circumstances of appeal grounds 1 to 5 and 2 above, the primary judge erred in law in failing to find that the plaintiff did not prove, on the balance of probabilities, that: (a) Mr Gatt suffered from asbestosis; and (b) Mr Gatt's lung cancer was caused by his exposure to asbestos as opposed to any other cause including, relevantly, his long-term and heavy cigarette smoking."
2. As I understand it, in the event the Court were to find error on the part of the primary judge, this ground of appeal invites this Court to make findings of fact favourable to Amaca on the disputed issue(s). Amaca sought to rely on s 32(2) of the DDT Act which confers on this Court power, on the hearing of an appeal under sub-s (1), to remit the matter "for determination by the Tribunal in accordance with any decision of the Supreme Court and may make such other order in relation to the appeal as the Supreme Court sees fit."
3. However, in circumstances where this ground of appeal is confined to errors or "points" of law, neither s 32(2) of the DDT Act, nor any other provision, confers on this Court the power to make findings of fact (Patrick Operations Pty Ltd v Comcare (2006) 68 NSWLR 131; [2006] NSWCA 142; see also Thaina Town (On Goulburn) Pty Ltd v City of Sydney Council (2007) 71 NSWLR 230; [2007] NSWCA 300 at [83] to [87]). If the outcome of the appeal had been that the primary judge's findings on both limbs of the Respondent's case were affected by an error of law, then the appropriate order would have been to remit the matter to the Tribunal.
4. I would reject this ground.

Additional Challenge: Special Costs Order

1. At the hearing of the appeal, Amaca was granted leave to add an additional ground of appeal challenging a special costs order made by the primary judge on 1 December 2021 (Roseanne Cleary as the legal personal representative of the estate of the late Fortunato (aka Frank) Gatt v Amaca Pty Limited [2021] NSWDDT 7). No separate submission was directed to this costs order. As I understand it, this challenge was dependent on the success or otherwise of Amaca's challenge to her Honour's principal judgment. As that has failed, this aspect of the appeal falls away.

Proposed Orders

1. As Amaca has failed to demonstrate an error of law in relation to both of the primary judge's critical findings it follows that I consider that the appeal must be dismissed.
2. I propose the following orders: (1) Appeal dismissed. (2) The Appellant pay the Respondent's costs of the appeal.
3. MITCHELMORE JA: I agree with Beech-Jones JA.

Endnotes

1. (2020) 102 NSWLR 303; [2020] NSWCA 122.
2. Primary judgment at [83].
3. Primary judgment at [18].
4. Primary judgment at [41]
5. Primary judgment at [19].
6. Primary judgment at [20].
7. Primary judgment at [27].
8. Primary judgment at [9].
9. Primary judgment at [10].
10. Primary judgment at [255] and [260] to [264].
11. Primary judgment at [260].
12. Primary judgment at [55].
13. Primary judgment at [57].
14. Primary judgment at [58].
15. Primary judgment at [59].
16. Primary judgment at [53].
17. Primary judgment at [42] to [63].
18. Primary judgment at [66].
19. Primary judgment at [76].
20. Primary judgment at [83].
21. Primary judgment at [88].
22. Primary judgment at [92] to [242].
23. Primary judgment at [230] to [242].
24. Primary judgment at [245].
25. Primary judgment at [255].
26. Primary judgment at [261].
27. Primary judgment at [166] and [185].
28. Primary judgment at [92] and [151].
29. Primary judgment at [153].
30. Primary judgment at [163]. 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 August 2022