Dasreef Pty Limited v Hawchar

Administrative Decisions Tribunal Act 1997 (NSW) s 119(1A)(c) Civil Procedure Act 2005 (NSW) s 60 Dust Diseases Tribunal Act 1989 (NSW) ss 11A, 32 Dust Diseases Tribunal Regulations 2007 LEGISLATION CITED: Occupational Health and Safety Act 2000 (NSW) Supreme Court Act 1970 (NSW) ss 75A, 101(2)(c) Uniform Civil Procedure Rules, r 42.40 (1) Workers Compensation Act 1987 (NSW) Workers' Compensation (Dust Diseases) Act 1942 (NSW) Workplace Injury Management and Workers Compensation Act 1998 (NSW)

Caltex Refineries (Qld) Pty Ltd v Stavar [2009] NSWCA 258; 259 ALR 616 ICI Australia Operations Pty Ltd v Workcover Authority of New South Wales [2004] NSWCA 55; 60 NSWLR 18 JLT Scaffolding (International) Pty Ltd (In Liq) v Silva (Court of Appeal, 30 March 1994, unreported) Makita (Australia) Pty Ltd v Sprowles [2001] NSWCA 305; 52 NSWLR 705 McGuirk v University of New South Wales [2010] NSWCA 1 Paric v John Holland (Constructions) Pty Ltd [1985] HCA 58; 59 ALJR 844 Perry v R (1990) 49 A Crim R 243 CASES CITED: Ramsay v Watson [1961] HCA 65; 108 CLR 642 Rhoden v Wingate [2002] NSWCA 165 Strinic v Singh [2009] NSWCA 15; 74 NSWLR 419 Trade Practices Comission v Arnotts Limited (No 5) (1990) 21 FCR 324 Tyco Australia Pty Ltd v Optus Networks Pty Ltd [2004] NSWCA 333 Wallaby Grip (BAE) Pty Ltd v Macleay Area Health Service (1998) 17 NSWCCR 335 Wheeler v Somerfield [1966] 2 QB 94 World Best Holding Limited v Sarker [2010] NSWCA 24

Cross on Evidence (7th Ed) TEXTS CITED: K R Handley, Spencer Bower and Handley: Res Judicata (4th Ed, LexisNexis) S Odgers, Uniform Evidence Law (8th Ed, Thomson Reuters)

PARTIES: Dasreef Pty Limited Nawaf Hawchar

COUNSEL: Mr T G R Parker SC, Mr D T Miller (Appellant) Mr H Marshall SC, Mr F Tuscano (Respondent)

SOLICITORS: Moray & Agnew Solicitors (Appellant) Keddies Lawyers (Respondent)

LOWER COURT JURISDICTION: Dust Diseases Tribunal

LOWER COURT MEDIUM NEUTRAL CITATION: Nawaf Hawchar v Dasreef Pty Ltd (No 2) [2009] NSWDDT 18

IN THE SUPREME COURT OF NEW SOUTH WALES COURT OF APPEAL 2009/298380

ALLSOP P BASTEN JA CAMPBELL JA

Tuesday 6 July 2010 DASREEF PTY LIMITED v NAWAF HAWCHAR [This headnote is not part of the reasons.]

This is an appeal against a judgment of the Dust Diseases Tribunal (Curtis J) dated 22 May 2009, brought pursuant to the Dust Diseases Tribunal Act 1989, s 32. The appellant, Dasreef, also appeals against costs orders made by his Honour on 15 July 2009.

Dasreef carried on a stonemasonry business, specialising in sandstone work. The respondent, Mr Hawchar, was employed as a labourer and stone cutter by Dasreef from 1999-2005. Mr Hawchar had worked with sandstone in Lebanon prior to his employment and from 2002-2005 did some private stonemasonry outside of work.

In late 2004, Mr Hawchar was diagnosed with scleroderma. By May 2005, his symptoms had become disabling. He ceased work for Dasreef and claimed and was paid workers' compensation benefits. In May 2006, Mr Hawchar was diagnosed with silicosis.

In October 2007, Mr Hawchar commenced proceedings in the NSW Dust Diseases Tribunal ("DDT") seeking common law damages on account of his scleroderma and silicosis. In October 2008, before the trial commenced, Dasreef made a formal offer of compromise under the DDT Regulations to pay $500,000 plus costs and workers' compensation retention.

On the scleroderma claim, Curtis J found Dasreef liable but, as scleroderma was not a "dust disease", damages would be limited in accordance with the Workers' Compensation Act 1987. However, Curtis J then made an order dismissing the scleroderma claim, on the request of Mr Hawchar's counsel during final submissions.

On the silicosis claim, Mr Hawchar was successful on liability. Curtis J assessed total damages for silicosis at $150,800, and having assessed employment exposure as representing 20/23 of the respondent's total exposure to silica dust, entered judgment in his favour for $131,130.43.

As to costs, Curtis J made an order that Mr Hawchar pay Dasreef's costs incurred in obtaining expert reports for the dismissed scleroderma claim and 40 per cent of Dasreef's costs in the preparation of those written submissions. However, Curtis J "capped" the amount payable by Mr Hawchar such that it would not reduce his damages below $100,000.

The questions on appeal concerning the findings on liability were: (i) Whether the primary judge erred in admitting the evidence of Dr Basden (Mr Hawchar's expert) because Dr Basden lacked relevant expertise, his opinion lacked reasoning, and because of the removal of assumptions supporting the evidence. (ii) Whether the primary judge erred in relying upon his experience as a judge in a specialist tribunal. (iii) Whether the primary judge erred in drawing an adverse inference from Dasreef's failure to call expert evidence from Mr Rogers, an occupational hygienist. (iv) Whether the primary judge erred in allocating 20/23 of the silica dust exposure to Dasreef without taking account of non-negligent exposure.

The questions in relation to the costs judgment were: (v) Whether the primary judge erred in refusing to award indemnity costs, as Dasreef's offer of compromise was more favourable than the judgment obtained. (vi) Whether the primary judge erred in limiting costs payable to Dasreef by Mr Hawchar for the dismissed scleroderma claim such that his judgment sum would not be reduced below $100,000.

Held (per Allsop P, Basten and Campbell JJA agreeing): (i) Dr Basden had relevant expertise to provide an opinion about the concentration of silica dust in Mr Hawchar's work environment. That his opinion was not based on precise measurement, but was an inexact estimate drawn from experience did not make his opinion inadmissible. That his opinion was based on assumptions of Mr Hawchar working in a tent did not undermine the legitimacy of his opinion to a point of such inutility to make it inadmissible. (ii) The primary judge did not err in drawing on his experience in a specialist tribunal. (iii) As to Mr Rogers not being called to give evidence, it was a legitimate conclusion to be drawn by the primary judge that his evidence would not have assisted Dasreef in that regard. (iv) While it can be expected that Mr Hawchar would have undergone some exposure to silica dust if Dasreef had not been negligent, there was no evidence as to what that was. The primary judge legitimately approached the matter on the basis that, factually, all Mr Hawchar's exposure at Dasreef was through Dasreef's negligence. (v) It was open to the primary judge to refuse to award indemnity costs for an exceptional case and to avoid substantial injustice. However, the primary judge erred in reasoning that the liability judgment gave rise to issue estoppels which prevented Dasreef from denying Mr Hawchar's entitlement to workers' compensation benefits for scleroderma and denying any future claim for damages for "scleroderma lung" that such condition was caused by Dasreef's breach of duty. Both parties appreciated that an acceptance of the offer would have put Mr Hawchar in a detrimental position in relation to the workers' compensation regime. Both sides were aware that Mr Hawchar was not claiming damages for scleroderma other than on the basis that scleroderma was a dust disease. (vi) An arbitrary view as to the sum Mr Hawchar should obtain from judgment is a consideration foreign to the exercise of the power as to costs. (vii) Because the incorrect finding of issue estoppels was important to the reasoning of the primary judge on costs and there being doubt as to how the primary judge approached the question as to how much Mr Hawchar should obtain from the judgment, the question of costs should be remitted to the primary judge for reconsideration.

IN THE SUPREME COURT OF NEW SOUTH WALES COURT OF APPEAL 2009/298380

ALLSOP P BASTEN JA CAMPBELL JA

Tuesday 6 July 2010 DASREEF PTY LIMITED v NAWAF HAWCHAR Judgment 1 ALLSOP P: This is an appeal under the Dust Diseases Tribunal Act 1989 (NSW) (the "DDT Act"), s 32 against orders made by the Tribunal (Curtis J) on 22 May and 15 July 2009 which included the following: "1. The plaintiff's claim for damages for scleroderma dismissed.

2. Judgment for the plaintiff against the defendant in the sum of $131,130.43.

4. Order pursuant to s 11A of the Dust Diseases Tribunal Act 1989 (NSW) that an award of further damages may be made with respect to silica induced carcinoma of the lungs, massive progressive fibrosis, tuberculosis, silica-tuberculosis, oesophageal dysfunction, renal disease, and scleroderma lung.

5. The defendant is to pay the plaintiff's costs of the proceedings excluding the costs incurred in obtaining reports from the forensic accountant and occupational therapist.

6. The plaintiff is to pay, on a party/party basis, the defendant's costs incurred in obtaining reports from the forensic accountant and occupational therapist and is also to pay 40 per cent of the defendant's costs incurred in the preparation of written submissions.

7. The sum of the costs referred to in order 6 is not to exceed $31,130.43." 2 The respondent to the appeal, the plaintiff below, Mr Nawaf Hawchar, contracted silicosis, having worked as a labourer and stone cutter for the appellant, the defendant below, Dasreef Pty Ltd ("Dasreef") between October 1999 and May 2005. 3 The DDT Act, s 32(1) and (2) governing the appeal to this Court from the Tribunal is in the following terms: " 32 Right of appeal to Supreme Court

(1) 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.

(2) The Supreme Court may, on the hearing of any appeal under this section, remit the matter to the Tribunal 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." 4 The grounds of appeal asserted by Dasreef included both errors of law in the decision of the Tribunal and questions as to the admission of evidence by the Tribunal during the course of the hearing. 5 Mr Hawchar pleaded his case both under the general law of negligence and for breach of statutory duty set by, amongst other laws, the Occupational Health and Safety Act 2000 (NSW) and Regulations thereunder. 6 In the common law count, Mr Hawchar pleaded (in para 7 of the Amended Statement of Claim ("ASC")) that he: "… was regularly exposed to and inhaled large quantities of silica dust generated whilst he, and others working in close proximity to him, used electrical and hand tools for the purposes of cutting, moulding and generally working with sandstone blocks." 7 The asserted breach of the duty of care was founded on a number of particularised allegations including: "Failure to supply and ensure the use of safe and suitable plant, gear and equipment so that the plaintiff might carry out the work without being exposed to unnecessary risk of injury. … Res ipsa loquitur.

Breaches of duties or obligations pursuant to the Occupational Health & Safety Act 2000." 8 The breaches of the statutory duty case were founded on a number of particularised allegations that included an allegation of a failure to ensure that Mr Hawchar was not exposed to airborne concentrations of silica dust that exceeded the relevant standard. 9 The appellant submitted that the only case run by Mr Hawchar below (either at common law or for breach of statutory duty) was to the effect that the relevant standard (being 0.2 mg/m3 over an eight hour time-weighted average for five working days) was exceeded by Dasreef in Mr Hawchar's working conditions. Mr Hawchar submitted that the case pleaded was wider than this and that a more general complaint was made about the excessive levels of respirable silica dust in his work environment. The debate becomes relevant at various points to which I will come. The judgment of Curtis J as to liability 10 The primary judge concluded that Mr Hawchar was a worker. There was no appeal against this finding. 11 The primary judge also concluded that scleroderma, from which Mr Hawchar was suffering, was not a "dust disease" as defined under the Workers' Compensation (Dust Diseases) Act 1942 (NSW). This conclusion, against which there was no cross-appeal, meant that the regime provided for under the Workers Compensation Act 1987 (NSW) (the "WC Act") for work injuries applied to this disease. The consequence of this conclusion for the running of Mr Hawchar's case will be discussed in due course. 12 The primary contest between the parties at the hearing that was relevant on appeal was whether the silicosis suffered by Mr Hawchar was caused by Mr Hawchar's work at Dasreef, and more specifically by Dasreef's breach of duty owed to Mr Hawchar to exercise reasonable care in the provision of a safe system of work. 13 The primary judge first examined the question of exposure by reference to the evidence of Mr Hawchar, which, with the exception of one matter, he accepted; of Mr Yousef, who was a co-worker of Mr Hawchar; of Mr Buono, the owner of a nearby factory; of Dr Leu and of Mr Hayek, the principal of Dasreef. The primary judge's findings on exposure were set out at [55]-[58] of his reasons: "[55] Before coming to Australia, Mr Hawchar worked part-time with stonemasons for a period of one year. In this work he was exposed to the inhalation of respirable silica generated from work by hand tools upon sandstone.

[56] Between 1999 and 2005 Mr Hawchar was exposed to the inhalation of respirable silica particles in the employment of Dasreef. He spent most of each day cutting and dressing sandstone with either a hammer and bolster, or an angle grinder. He frequently worked on five consecutive days cutting with an angle grinder. On each of those days the cumulative time operating the angle grinder exceeded 30 minutes. On many occasions he worked in close proximity to other men operating angle grinders. Mr Hawchar wore a mask supplied by his employer when he was operating an angle grinder but not otherwise.

[57] Between 2002 and 2005 Mr Hawchar was occasionally exposed to the inhalation of respirable silica particles on weekends when he dressed sandstone with angle grinders and chisels in the course of private work.

[58] Having regard to the duration and concentrations of exposure, I assess the relative contributions to Mr Hawchar's total silica burden as one part the Lebanon exposure, two parts the exposure in the course of his private work, and 20 parts the exposure in the employment of Dasreef." 14 There was no appeal from these findings. 15 The debate on appeal concerned the primary judge's finding of breach of duty and his Honour's use of the evidence of Dr Basden in that regard. 16 The primary judge set out Dr Basden's qualifications in [60]-[63] of his reasons as follows: "[60] Dr Basden graduated as a Bachelor of Science in Applied Chemistry from the University of New South Wales in 1954. In 1960 he was awarded his PhD. He is a founding member and fellow of the Clean Air Society of Australia and New Zealand and a fellow of the American Industrial Hygiene Association. He is an associate member of the American Conference of Governmental Industrial Hygienists and of the Australian Institute of Occupational Hygienists.

[61] Between 1954 and 1987, Dr Basden lectured in Mining Engineering and related topics at the University of New South Wales. He established a dust laboratory, and taught subjects which included 'Mining Hygiene and Dust Control' ' and 'Practical Aspects of Air Pollution Measurement and Control' . His many publications include 'Air Pollution Measurement and Control' , 'Measurement of Fugitive Particulate Emissions from Mining Operations' , 'Air Pollution Guide-Particulate Matter' , 'International Standards and Legislation on Dusts' , 'Characterisation of Fugitive Particulate Emissions from Industrial Sites' , 'Monitoring of Fugitive Dust From Industrial Sites' and 'The Rapid Measurement of Airborne Particulate Concentrations and Applications to Evaluation of Source Emission Factors' .

[62] Dr Basden has supervised candidates for Masters degrees in studies that include The Physical Characterisation of Ambient Atmospheric Particulates , and The Generation and Properties of Airborne Particulate Matter from Industrial Grinding Operations.

[63] From 1987 until the present time, as an Engineering and Environmental Consultant, Dr Basden has conducted many field and laboratory investigations into air pollution, and workplace atmospheric contamination. He is experienced in the measurement of respirable dust concentrations, and familiar with Australian/New Zealand Standard 1715 entitled 'Selection, use and maintenance of respiratory protective devices'." 17 The relevant standards to protect against the deleterious effects of inhalation of dusts containing free silica were described by the primary judge at [65]-[71] of his reasons, as follows: [65] The Australian National Health and Medical Research Council from about the 1960s adopted the guidelines of the American Conference of Governmental Industrial Hygienists which limited the 'permissible concentration' for airborne dusts containing more than 50 per cent silica at 5 million particles per cubic foot of respirable particles of between 0.5µm, and 10µm, in diameter. In 1996 WorkSafe Australia adopted 0.2 mg/m 3 as the maximum time weighted average (TWA) to which a person may be exposed in industry. This is the average airborne concentration calculated over a normal eight-hour working day for five working days. (The evidence does not spell this out, but I assume that this standard relates to particles of respirable size.)

[66] Australian/New Zealand Standard 1715 is directed towards precautions necessary to achieve reduction of inspired particles to below harmful levels. The standard states that as a general principle 'No person should be exposed without suitable protection to an atmosphere that is or may be injurious to health', and that 'If efforts to prevent or control the hazard at the source are unsuccessful, suitable respirators should be provided and used'.

[67] The standard requires that a person exposed to an atmosphere containing excessive concentrations of harmful dust be provided with a respirator capable of filtering those particles to concentrations below the acceptable standard.

[68] Pursuant to the standard, respirators are denoted as P1, P2, and P3, indicating increasing efficiencies of filtration. In general terms, P1 respirators reduce the concentration of respirable particles by a factor of 10, P2 by a factor of 50 and P3 by a factor of 100.

[69] The necessary protection factor in a given environment is defined as the ratio between the concentration of the contaminant outside the respirator to the concentration inside the respirator, ie breathed by the wearer.

[70] The standard states that: 'The required minimum protection factor for any given situation is that factor necessary to reduce the exposure of the wearer to below an accepted level or exposure standard or to minimise the potential exposure.'

[71] The protection factor and required minimum are expressed in the following equations:

" 18 From these standards, the primary judge summarised the heart of the case against Dasreef, on Dr Basden's evidence, at [72]-[73] of his reasons, as follows: "[72] In accordance with this standard the concentration of airborne particulates inhaled by Mr Hawchar from inside his mask should not exceed the proclaimed concentration standard of 0.2 mg/m 3 of respirable particles. Dr Basden says that the actual dust concentrations generated in Mr Hawchar's breathing zone generated by the cutting wheel of the angle grinder 'Most certainly would not be from half to two ten-thousands of a gram per cubic metre of air, but more realistically would be of the order of a thousand or more times these values [0.2g] or even approaching one gram, or thereabouts, per cubic metre. ' [73] Dr Basden says that the minimum protection factor required by the standard in order to protect Mr Hawchar was well in excess of 100 plus, and could realistically approach 1000, and that the only suitable type of respirator would be a Powered Air Purifying Respirator fitted with a PAPR-P3 filter. He says that there are … many such respirators available in Australia." 19 The primary judge then at [74]-[81] of his reasons described the submissions of Dasreef as to the lack of qualifications of Dr Basden. Given the centrality of this same debate to the resolution of the appeal, it is helpful to set out all these paragraphs of his Honour's reasons, notwithstanding their length: "[74] In cross-examination Mr Parker SC for Dasreef established that while Dr Basden had experience in measuring the atmospheric concentration and respirable fractions of a number of dusts, he has not measured the respirable fraction of dry ground sandstone. He has measured respirable concentrations of dust in the vicinity of wet cutting of sandstone and of silica on construction sites. On one occasion he observed the dust generated by the application of the grinding wheel to sandstone, and he has seen a video of this process tendered in evidence by the defendant. He said that from his experience in observation and measurement he was able to form an opinion based on those observations alone, within general parameters.

[75] Mr Parker further elicited from Dr Basden admissions that he could not express a numerical opinion about Mr Hawchar's exposure to respirable silica, that he could not express an opinion about the amount of dust that Mr Hawchar would have inhaled during his time with Dasreef and could not express a numerical opinion about the time-weighted average of Mr Hawchar's exposure to silica.

[76] These admissions are to be seen in the context of these further questions:

Q.Dr Basden, you are not in a position to say based on specialised knowledge based on your study, training or experience what the concentration of respirable silica would have been in Mr Hawchar's breathing zone when it was cutting stone with an angle grinder at Dasreef?

Q. You would not claim, would you, to be able to express an opinion based on specialised knowledge that you have as a result of your study, training and experience, that the existence of a visible dust cloud when one cuts with an angle grinder enables one to quantify the amount of respirable silica in the air in that cloud?

A. That's correct, the actual figure couldn't be given.

Q. Did you say 'couldn't be given', the actual figure?

A. It'd be difficult to say, your honour, precisely. I mean there's a lot of dust and a visible cloud and it has a long probability spread part of which of cause is going to be in the respirable size [range] but as for amounts, no, without actually taking measurements it would be difficult to quantify exactly.

[77] After these exchanges, when asked upon what basis did he express the opinion that the dust in Mr Hawchar's breathing zone was in the order of a thousand or more times that permitted by the standard as a time weighted average, Dr Basden said:

Well, general knowledge of being in this area of dust for quite some time, your Honour, being used to the amounts of dust when seen on a microscope slide when dispersed in the air, what the clouds look like, the 0.10 milligrams of dust is not a very big amount. I've written some reports which actually have a photograph of 10 mg on a microscope slide sitting on the balance showing it is 10 mg that's there. It's a very, very small amount and that dispersed in one cubic metre of air would be virtually invisible but would show up in a very large room, but therefore when there are clouds of visible dust within an area of a metre or so of the source the concentrations are going to be very high.

[78] Dr Basden also gave this evidence in re-examination:

Q. Having viewed what you see on the DVD and assuming that it was using a grinder of that type that the plaintiff was involved in, what effect, either by strengthening or weakening your opinion about the view that the actual dust concentrations that Mr Hawchar was exposed to would have been in the order of a thousand or more times these values, what does the viewing of that do to your opinion?

[79] The video watched by Dr Basden is in evidence. At 15 minutes 39 seconds it demonstrated that the visible cloud of dust generated by the angle grinder enveloped the head of the worker.

[80] Dr Basden's position is made abundantly clear in later evidence:

Q. You have expressed an opinion, a numerical opinion, as to the amount of dust of respirable silica in Mr Hawchar's breathing zone, have you. A---In this statement here.

Q. By that statement are you or are you not expressing an opinion as to what numerically you think the concentration of respirable dust in Mr Hawchar's breathing zone would have been when he undertook the task that you saw depicted in the photograph. A---I couldn't give a precise figure, that's only just a general ballpark estimate type of figure because you wouldn't get a precise figure unless an actual measurement were made with the instruments.

Q. You were expressing the opinion that the level of dust in that cloud of dust produced by the grinder during the time that the grinder was operating would have greatly exceeded the level of point 2 milligrams per cubic metre. A---Yes.

Q. But you were not seeking to be precise as to whether it would have exceeded it by five times or 500 times. A---More like 500 or a thousand times is what I stated there. There would have been in those clouds that I witnessed at that time something of the order of a fraction of a gram, point something of a gram, not point 0-something or other, or point double 00-something of a gram.

Q. I do not understand that that particular statement that you have made about it ranging between 500 times or a thousand times. A---There again, it's only a ballpark to justify the reason I was recommending the protection factor of about a thousand for the use of a VAPR respirator. That was the purpose of it.

Q. That figure or that range of figures or that ballpark figure, as I think you have described it. A---Yes.

Q. That figure, I think we have established, is not based on any comparison with any measurements that you have undertaken of respirable silica, correct?

Q. Yes. A---I have undertaken work in the past to determine the amount of dust and clouds in the air over lots of situations and it's just the sort of opinions that I have come up with. I've measured dust clouds from time to time and weighed the filters afterwards.

[81] Concessions by Dr Basden that the atmospheric concentration of silica particles to which Mr Hartcher [sic] was exposed 'could be' less than 1000 times the prescribed concentration constitute no more than an admission that he may, possibly, be wrong in his judgment that the concentration was, more probably than not, 'realistically…in the order of a thousand or more times these values [0.2 mg/m 3 ] or even approaching 1 gram or thereabouts, per cubic metre'. " 20 The primary judge then, at [82]-[86] of his reasons, carried out some calculations using Dr Basden's assessment to come to the comfortable conclusion that the relevant standard had been exceeded. His Honour said: "[82] A simple calculation may be made upon the basis of Mr Hayek's evidence that a man engaged in cutting stone through the course of one day would use the angle grinder for approximately 30 to 40 minutes, and Dr Basden's opinion that during this time he would be exposed to dust concentrations at least 1000 times greater than the permissible limit of 0.2 mg/m 3 per cubic metre. Accepting for the moment that the P2 mask provided to Mr Hawchar fitted perfectly and provided a protection factor of 50, the concentration of respirable particles within the respirator when cutting was 1000 ÷ 50 × 0.2mg/m 3 = 4 mg/m 3 .

[83] The standard TWA of 0.2mg/m 3 permits the accumulation of 40 hours × 0.2mg/m 3 = 8mg/m 3 . If a man is exposed for 30 minutes on each of five days to a concentration of 4mg/m 3 his cumulative weekly exposure is 2.5 hours × 4 mg/m 3 =10 mg/m 3 . The TWA of this exposure over 40 hours is then 10 mg/m 3 ÷ 40 = 0.25mg/m 3 . This exceeds the permissible limit. If he were exposed for 40 minutes each day his TWA rises to 0.33 mg/m 3 .

[84] This exercise assumes that the atmospheric concentrations of respirable silica completely disappear the instant the grinder is turned off, and that no other grinders were being used by men working beside him. Dr Basden, who has conducted studies on the dispersion rate of respirable silica particles, said that the finer particles, below 10µm, (the respirable fraction) remain almost permanently suspended in the air until removed by contact with a solid surface or by rain. On windless days the respirable particles remained in and about Mr Hawchar's breathing zone to be inhaled by him without the protection of the P2 mask that he wore, as instructed, only when cutting. Mr Buono has described the clouds of dust that, for several hours, surrounded the men cutting sandstone in Dasreef's yard.

[85] Further, the additional activities of cutting, splitting and dressing sandstone with a hammer and bolster also generated dust that does not feature in the calculation. The first study that showed a relationship between scleroderma and silica, by a Dr Bramwell in Scotland early in the 20th century, related to stonemasons working on stone with hammers and chisels but without respirators. Dr Helen Englert, the defendant's expert, when asked whether persons working with hammers and chisels on sandstone without respirators were at risk, replied 'Absolutely'.

[86] The video to which I earlier referred, at five minutes 39 seconds, demonstrated that visible dust was liberated by the application of a hammer and bolster to sandstone placed within 50 cm of the worker's nose and mouth. This video, filmed for, and tendered by, the defendant, confirmed that masks were worn when cutting stone with an angle grinder, but not when using a hammer and bolster. " 21 The primary judge then referred to two other considerations in his fact finding against which challenge was made: his position as a judge in a specialist jurisdiction and the failure of Dasreef to call an expert witness, an occupational hygienist, Mr Alan Rogers, who, it was admitted, had been qualified. In regard to these two matters, his Honour said the following at [87]-[88] of his reasons: "[87] Of greatest significance is the fact that Mr Hawchar suffers from silicosis. The Dust Diseases Tribunal is a specialist jurisdiction and I am permitted to take into account my experience that this disease is usually caused by very high levels of silica exposure ( JLT Scaffolding International Pty Ltd (In Liq) v Silva, New South Wales Court of Appeal, 30 March 1994, unreported ).

[88] Dasreef has admitted that it qualified Mr Alan Rogers, an occupational hygienist, for the purpose of giving evidence in this case. He is not called. I draw the inference that his evidence would not advance the defendant's case that, in the absence of measurement, no conclusion may be made as to the probable concentration of respirable silica dust in the breathing zone of a person cutting sandstone with an angle grinder." 22 The primary judge then set out his conclusions concerning exposure and breach of duty based on the expert evidence saying, at [89]-[91] of his reasons: " Findings on expert evidence [89] Mr Hawchar, when using an angle grinder in the employment of Dasreef, was frequently exposed to high concentrations of dust, which exceeded the maximum time weighted average of 0.2 mg/m 3 for one week mandated by the WorkSafe Australia standard. He was also, when cutting with a hammer and bolster without wearing a mask, or in the vicinity of persons cutting with hand tools or angle grinders, exposed to sufficient concentrations of dust to create the risk of contracting a silica-related disease.

[90] The P2 mask provided by Dasreef to Mr Hawchar was adequate to protect him from silica inhalation when cutting with a hammer and bolster. On the evidence of Dr Englert, stonemasons were at risk of contracting silica-related diseases if such a mask was not worn while performing this work.

[91] The P2 mask was inadequate to protect Mr Hawchar from silica inhalation when working with an angle grinder. A suitable mask, a Powered Air Purifying Respirator fitted with a PAPR-P3 filter was reasonably available for purchase by Dasreef."

It is the extent to which these findings are based on Dr Basden's evidence that forms the first important issue in the appeal. 23 The primary judge then made findings about Mr Hawchar's silicosis being caused by his work at Dasreef, such findings being based in part on the evidence of Professor Henderson. These findings, against which there was no appeal, were at [92]-[94]: " Was the silicosis caused by Mr Hawchar's work at Dasreef? [92] Silicosis is a diffuse pulmonary fibrosis caused by the inhalation of excessive quantities of silica-containing dust. The sole cause of silicosis is the inhalation of excessive quantities of silica particles. Dasreef admits that Mr Hawchar suffers from silicosis. There is no suggestion that Mr Hawchar was exposed to silica particles other than in Lebanon, in the employment of Dasreef, and in his private building work. His disease has been caused by the cumulative effect of all three sources.

[93] Professor Henderson says that short latency intervals are unusual, but not unknown, and that latency intervals of about 5-10 years characterise accelerated silicosis, suggesting that Mr Hawchar's silica exposure was intense. Professor Henderson atttributes Mr Hawchar's silicosis to a history of exposure to silica dust over a period of six years beginning in 1999.

[94] It is now apparent that the exposure in Lebanon is also a contributory cause, although, being far less intense, I believe it to be a minor cause." 24 At this point, it should be noted that it was submitted on behalf of Mr Hawchar that even if Dr Basden's evidence was wrongly admitted, there was ample evidence upon which to support a conclusion that Mr Hawchar's exposure at Dasreef was excessive and caused by breach of duty. One matter to which attention was directed in this regard was the rapid on-set of his disease leading to the inference that exposures to which Mr Hawchar was subjected were very high. The difficulty with this approach is that it is not how the primary judge approached the matter. Dr Basden's evidence was important to the primary judge's reasoning. It was not the only material or consideration that the primary judge relied upon for his conclusion as to breach, but it was at the centre of his reasons. Further factual analysis would need to be undertaken to reach the conclusion asserted, absent reliance on Dr Basden's evidence. That is not the function of this Court in an appeal under s 32. There may be circumstances where the demonstration of legal error in the Tribunal does not, on the facts found by the Tribunal, persuade this Court of the materiality or operativeness of any such error: Caltex Refineries (Qld) Pty Ltd v Stavar [2009] NSWCA 258; 259 ALR 616 at [16] and [145]. Nevertheless, in an appeal under s 32, this Court does not undertake an evaluation of the evidence in order to assess the correctness of an alternative factual hypothesis that might support the orders made, as it might do in considering a notice of contention under an appeal governed by the Supreme Court Act 1970 (NSW), s 75A. 25 The primary judge then, at [95] of his reasons, made findings about silicosis as a divisible disease, as follows: "Silicosis is a divisible disease. In accordance with my earlier findings as to relative concentrations of exposure, I find that as to 20 parts in 23 the silicosis was caused by Mr Hawchar's work at Dasreef." 26 A further complaint made on appeal was that the primary judge did not further divide the disease and reduce Dasreef's proportion for so-called non-negligent exposure. It was submitted that there was a degree of exposure for which Dasreef could not be criticised (that is below the 0.2 mg/m3 standard) and it should receive a "credit" for that. 27 The primary judge then, at [96]-[153], dealt with the disease of scleroderma, the medical evidence in relation thereto and the relationship between the silica dust, silicosis and scleroderma in terms to which it is unnecessary to refer. 28 At [154]-[155], the primary judge then set out his conclusions on breach of duty as follows: " Did Mr Hawchar's injuries result from a breach of duty by Dasreef? [154] Because Dasreef does not rely on allegations of contributory negligence it is unnecessary that I address statutory breaches of duty.

[155] Mr Hawchar's injuries of silicosis and scleroderma were reasonably foreseeable by Dasreef as possible consequences of the work upon which he was engaged. Those injuries could have been prevented by Dasreef's providing to Mr Hawchar a suitable respirator, then reasonably available, for use when he was cutting with an angle grinder. Further, Dasreef should have warned him of the risks associated with cutting sandstone with a hammer and chisel without a mask, and required that he use the P2 mask when he did this work, or when stone cutting was performed by others in his vicinity. I find that Mr Hawchar's injuries result from Dasreef's breach of duty." 29 At [156]-[165], the primary judge dealt with damages. These conclusions are not in contest. 30 At this point, before going to the balance of the primary judge's reasons as to scleroderma, his order under the DDT Act, s 11A and the costs judgment, it is convenient to deal with the appeal insofar as it concerns Dasreef's breach of duty and the consequences thereof.

Grounds of appeal concerning the substantive judgment on liability 31 The grounds of appeal in this respect that were pressed were as follows:

(a) The primary judge erred in admitting the evidence of Dr Basden (ground 1(a)) because:

(i) Dr Basden lacked relevant expertise; (ii) of a lack of explanation of, or reasoning supporting, his opinion; and (iii) of the removal of a central assumption supporting his opinion.

(b) The primary judge erred in relying upon his experience as a judge in a specialist tribunal (ground 1(ba)).

(c) The primary judge erred in drawing an adverse inference from Dasreef's failure to call expert evidence from Mr Rogers, the occupational hygienist (ground 1(b)). 32 During the hearing of the appeal, the appellant abandoned a ground (ground 1(c)) concerned with the primary judge's finding of exposure on a time weighted average basis. This abandonment carried with it the aspect of ground 1(c) that involved a complaint that [82] of the primary judge's reasons was legally flawed in the factual findings made, to the extent that it is implicit in that paragraph "that Mr Hawchar's exposure in the work that he did when the angle grinder was being used corresponded with the number that Dr Basden had come up with": see Appeal Transcript 5 March 2010 p 14 ll 45-47.

His asserted lack of experience 33 The objection to the evidence of Dr Basden and the ruling upon it by the primary judge were not clearly revealed by the record of the hearing. It was submitted that all of Dr Basden's evidence was taken on the voir dire. It was accepted by Dasreef, however, that the primary judge's utilisation of Dr Basden's evidence was an implicit ruling on that evidence and the admission of the evidence on the voir dire as evidence in the proceedings. 34 I am content to work on that basis. Mr Hawchar did not oppose that course. Nevertheless, with all due respect to the experienced counsel who ran the hearing and to the very experienced primary judge, and without intending any personal criticism, it should be said that the admission and rejection of evidence and the reasons therefore (if given) are important matters of record in any trial, but in particular one where the rights of the parties to appeal are limited as they are under the DDT Act, s 32. Rulings on evidence and associated steps (such as giving reasons, to the extent they may be given, taking evidence on the voir dire and adopting evidence taken on the voir dire into the evidence in the hearing proper) should be clearly recorded, so that the rights of appeal of the parties are not compromised. 35 The opinion of Dr Basden referred to by the primary judge at [72] of his reasons ([18] above) was said by the appellant not to be one which he could give because of a lack of relevant expertise in measurement of silica in dust. 36 Dr Basden's expertise has been and had to be assessed by reference to the totality of evidence given by him. The primary judge referred to that expertise at [60]-[63] of his reasons ([16] above). His Honour also referred to parts of the cross-examination at [74]-[81] of his reasons ([19] above). It would be burdensome to set out, verbatim, all the examination and cross-examination. There was, however, ample material from Dr Basden's evidence to support the conclusion that he had the relevant expertise to proffer an opinion concerning the measurement of silica dust in the way he did. 37 The material recited by the primary judge is sufficient to permit that conclusion. Dr Basden stated clearly that he had undertaken work in the past to determine the amount of dust in many situations. He said that he had measured dust clouds. He said his opinion was just the sort of opinion that he has drawn in the past on many occasions. If he was accepted in this evidence (as he was) his experience was established. Dr Basden's oral evidence was contained over forty pages at the hearing on 5 November 2008. It revealed a deep and extensive experience with dust, including silica dust, in industrial and occupational health and safety contexts. This involved measurement, ventilation and personal protection equipment. He was clearly familiar with measurement techniques. I would particularly refer to the following pages of the transcript (using Black Book references and trial transcript pages in parentheses): Black 145 (193), 150 (198), 151 (199), 153 (201), 154 (202), 156 (204), 157 (205), 159 (207), 160 (208) to 166 (214), 168 (216) and 170 (218) to 173 (221). 38 Whether or not the opinion was acceptable or whether it suffered any particular defect is another thing. Dr Basden had the background and relevant expertise to proffer an opinion about the concentration of airborne silica dust.

The asserted lack of expressed reasoning 39 The appellant submitted that, conformably with the reasons of Heydon JA (as his Honour then was) in Makita (Australia) Pty Ltd v Sprowles [2001] NSWCA 305; 52 NSWLR 705, the opinion in the report of Dr Basden relied upon by the primary judge just was not rationally explained by Dr Basden. The report itself contained some (though limited) elucidation of the basis of the conclusion. The opinion must, however, be assessed in the light of the whole of Dr Basden's evidence. Dr Basden was given assumptions that included the following: "Mr Hawchar is suffering from silicosis allegedly contracted through the inhalation of silica bearing dust, while in the employment of the defendant between 21 October 1999 and May, 2005. During this period Mr Hawchar was employed as a stone worker who was involved in cutting and laying stone, usually sandstone. Depending on the nature of the job, Mr Hawchar on a daily basis spent from one hour to all day cutting stone, usually standstone, and generally by power tools. This operation generated large quantities of airborne dust. While performing this work, Mr Hawchar at all times wore a mask provided by his employer, but he alleges that dust penetrated these masks because of gaps between them and his face. Mr Hawchar also alleges that about 20 to 30 times each year during the period of his employment he worked within a plastic enclosure or 'tent', erected to minimise the spread of fugitive dust to neighbouring properties. One side of this enclosure or tent was fitted with an exhaust fan to remove the dust therefrom, but nevertheless Mr Hawchar claims that in spite of this the enclosure only served to concentrate the dust in his working / breathing zone. He further alleges that due to the increased concentration of dust he would have to take a break approximately every hour because of troubled breathing." He also saw the DVD which was in evidence showing cutting of sandstone at Dasreef's premises. 40 In his report, Dr Basden said: "… The actual dust concentrations generated in Mr Hawchar's breathing zone, which would be no more than 50 or 60 cm from the cutting wheel (as indicated by the photograph supplied; c.f. paragraph 8 above), presumably were never measured with the appropriate instruments while work was in progress. However, it most certainly would not be from half to two ten-thousandths of a gram per cubic metre of air, but more realistically would be of the order of a thousand or more times these values or even approaching one gram, or thereabouts, per cubic metre. (Only once can I recall actually observing sandstone being dry-cut in the open air by portable powered angle grinders, at a monument being erected at the entrance to a country town in NSW. Each of the two operators was enveloped by dense clouds of highly visible fugitive dust, and neither was wearing a respirator of any type! In the case of Mr Hawchar, the defendant found it necessary to erect a 'tent' fitted with an exhaust fan 'to attempt to minimize the dust pollution caused to neighbouring properties when the stone was being cut', which indicates the production of considerable quantities of visible dust). It should be noted that not all of the dust in the visible clouds being generated by the cutting wheels would be in the 'respirable' size range, which means an equivalent aerodynamic diameter (EAD) of below 4 μ m. The actual clouds would consist of particles from about 20 or perhaps 30 μ m downwards, as larger ones will settle rapidly by gravity and not remain in the airborne state. However, a considerable proportion of the size distribution of the suspension would be 4 μ m and below, and hence would constitute the 'respirable' fraction of the dust cloud." (emphasis in original)

41 The cross-examination of Dr Basden revealed that his opinion was not based on a precise measurement or a view expressed with precision, but rather an estimate drawn from his experience. It is clear from the extract recited by the primary judge at [77] of his reasons that Dr Basden's view was that it was obvious from his experience that the dust concentrations were very high based on his knowledge of Dasreef's practice and from applying his experience to that knowledge. That came in part from his statement (Black 163 (211)) that nuisance dust (by which he meant the limit that should not be exceeded) would be barely visible in a room. The clouds of dust produced in the performance of work described in the evidence was a foundation for the estimate given by him. This conclusion and reasoning was supported by the evidence that he gave as to the fractions of respirable dust in all dusts: Black 153 (201), 155 (203), 163 (211), 170 (218), 171 (219) to 176 (224) and 180 (228) to 182 (230). 42 From the debate reflected in the evidence of Dr Basden, his reasons for coming to the opinion are clear: his experience and specialised knowledge allowed him to say that given that dusts have a consistent fraction of respirable content and that given Mr Hawchar was working in clouds of silica as the evidence revealed, an inexact estimate of the concentration of respirable silica dust was what he said it was - a thousand times the acceptable level of the standard. 43 No doubt, it was contestable and inexact. But it was then for someone qualified as an expert to say that his estimate was worthless, or of little weight, or for some other reason unreliable. 44 A lack of reasoning did not make his opinion inadmissible.

The removal of assumptions supporting the evidence 45 The appellant submitted that various concessions made by Dr Basden destroyed the foundation of his evidence thus making it inadmissible. 46 First, it was submitted that his evidence was that his opinion was founded on Mr Hawchar working in a tent. The findings by his Honour about the use of the tent were that this occurred on only two or three occasions. These findings, it was submitted, destroyed Dr Basden's evidence. That is not how Dr Basden's evidence should be read. In the relevant passages in the Black Book at 184-185 (232-233), Dr Basden was referring to the assumptions in his report that I have earlier set out ([39] above). Though the frequency of the use of the tent was falsified by the primary judge's findings, Dr Basden's evidence should not be read as only directed to measurement in a tent. Its legitimacy was not undermined to a point of such inutility as to make it inadmissible: cf Makita at [85] and Rhoden v Wingate [2002] NSWCA 165. It is unnecessary to explore any debate as to the residual operation of the basis rule under the Evidence Act 1995 (NSW) that may perhaps be seen to arise from an application of Makita: see generally S Odgers, Uniform Evidence Law (8th Ed, Thomson Reuters) at 323-327 [1.3.4320]. The difference between Dr Basden's assumption about the tent and the facts as found would not be sufficient under the basis rule to make inadmissible his opinion: Ramsay v Watson [1961] HCA 65; 108 CLR 642 and Paric v John Holland (Constructions) Pty Ltd [1985] HCA 58; 59 ALJR 844 at 846. As Samuels JA said in the Court of Appeal in Paric ((1984) 2 NSWLR 505 at 509-510) the importance of any discrepancies between what is assumed and what is proved is for the tribunal of fact to assess. This was discussed by Beaumont J in Trade Practices Commission v Arnotts Limited (No 5) (1990) 21 FCR 324 at 326-330, which was approved by Gleeson CJ (with whom Mahoney JA and Studdert J agreed) in Perry v R (1990) 49 A Crim R 243 at 249. 47 Secondly, on a number of occasions, such as in the passages referred to and cited by the primary judge at [74]-[76] of his reasons (see [19] above), Dr Basden expressed qualification as to the difficulty or impossibility of precise measurement. That did not destroy the validity of his opinion. The opinion was intended as an estimate.

The relevance of Mr Hawchar's silicosis - how the case was run and the experience of the judge in a specialist court 48 The complaint as to [87] of the primary judge's reasons (see [21] above) was partly based on how it was said the case was run and partly on what was said to be the legal flaw in the approach. 49 As to the former, contrary to the submission of the appellant, the case was run by reference simply to excessive levels of dust. That is made clear by the pleadings to which I have referred. The statement of the primary judge is within the particulars and in accordance with the medical evidence of Dr Henderson on 3 November 2008, as follows: "Q. Let me ask you this question, suppose that Mr Hawchar had been presented to you without any history of above background silica exposure, would you[r] diagnosis still be silicosis. A. Other factors radiologically would enter into the differential diagnosis but if, as a pathologist, I were given, say, a lobe of his lung and I were able to examine that and I detected multiple silicotic nodules then I would make a diagnosis [of] silicosis and if there were no history I would indicate that a history of exposure must have been overlooked, there must have been a history of exposure to above background concentrations of crystalline silica particles in the atmosphere. After all, the appearances of silicotic nodules are very characteristic. … Q. My question is, are you able to quantify what excessive means in that context. A. I cannot draw sharp boundaries in this respect and the [dose] response relationships are less well defined than they are, for example, for asbestos dust inhalation and asbestosis. However, when I've used the word, excessive, there I've done it in the context that silica is the most abundant mineral in the earth's crust in its various forms and that we all have inhaled silica containing dust so that the diagnosis of silicosis requires the demonstration of excessive above-background silica dust exposure either high-intensity exposure for short periods of time or lower but excessive inhalation for more protracted periods of times so that you need to take into account the occupational history if you are dealing with a clinical diagnosis of silicosis. Having said that, I cannot put numerical values on this, all I would say [is] that usually the disease is the outcome of often times intense exposure over a period of a few years or of a less intense exposure over more protracted periods of time. Q. But excessive means above background. A. It means well above background. Q. How far above background. A. Again, I cannot put a numerical quantifier on that, all I would say is substantially or highly above background. Q. You are unable to quantify it. A. I would not try and quantify it in numerical terms. I don't think one can do so as a matter of biological observation. Biology doesn't have sharp boundaries between significant and non-significant effects in terms of numerical quantifiers. Q. If this man had been presented to you and his history had been, instead of what you have been provided with, that he had worked for three months about 20 years before as a labourer in a stone masonry business, would that or could that qualify as giving rise to excessive exposure of the sort referred to in your definition?"

This was reflected in the primary judge's findings at [93] of his reasons. 50 By referring to the evidence I am not intending to find facts. Rather, the pleadings, the evidence and the primary judge's approach all reflect an approach to the case other than one based on precise measurement. Thus, the first basis of the argument for error in [87] falls away. 51 The second basis was a challenge to the primary judge's ability to use his position in a specialised court. The legitimacy of a judge of the Dust Diseases Tribunal taking account of his experience in understanding a dust disease is established by ICI Australia Operations Pty Ltd v Workcover Authority of New South Wales [2004] NSWCA 55; 60 NSWLR 18 at 62-65 [216]-[234] (per McColl JA, with whom Mason P agreed and Meagher JA generally agreed); and JLT Scaffolding (International) Pty Ltd (In Liq) v Silva (Court of Appeal, 30 March 1994, unreported) at 12 per Kirby P. 52 Dasreef sought to distinguish the line of authority applied in ICI to tribunals, such as the Workers Compensation Commission, that had particular administrative responsibilities. No such distinction need be drawn. It was not drawn in ICI, which concerned the Dust Diseases Tribunal. 53 The distinction, drawn by the learned author of Cross on Evidence (7th Ed) and referred to by McColl JA in ICI at 64 [229] and by Beazley JA in Wallaby Grip (BAE) Pty Ltd v Macleay Area Health Service (1998) 17 NSWCCR 335 at 365, between (a) a specialist tribunal drawing on its experience to enable it to understand quickly the evidence and to draw appropriate inferences from the evidence and (b) special knowledge that permits it to assert the existence of particular facts (in the latter case, procedural fairness requiring the parties to be given an opportunity to deal with the fact) can be seen as a legitimate one. It does not, however, affect the legitimacy of the approach of the primary judge here. The case was run on the basis contended for by Mr Hawchar - that there was excessive silica dust, that his exposure was heavy and that, as Dr Henderson said, his silicosis tended to support a conclusion that Mr Hawchar was exposed to excessive, in the sense of unsafe, levels of silica. The primary judge's remarks in [87] can be seen to be using his expertise to draw more readily conclusions from what appeared in the evidence. 54 Nothing in Strinic v Singh [2009] NSWCA 15; 74 NSWLR 419 is to the contrary of this approach. Indeed, in Strinic at [58], Beazley JA (with whose reasons Ipp JA and Basten JA agreed) noted the principles and practices that apply in specialist courts, referring to JLT Scaffolding, and distinguished the position of the District Court as a court of general statutory jurisdiction.

The failure to call Mr Rogers 55 The use by the primary judge, at [88] of his reasons ([21] above), of the failure to call Mr Rogers was legitimate. The primary judge had a factual controversy before him. He had evidence from Dr Basden of the character already discussed. The cross-examination of Dr Basden implicitly asserted the unreliability and lack of strength of the opinions expressed by him. It was submitted before the primary judge and on appeal that Dr Basden's evidence was so lacking in explanation that it should be rejected. An assumption underlying that submission was that the lack of explanation made the opinion palpably weak. I have already expressed my view that Dr Basden's evidence did not lack rational explanation and expression. That did not, however, require the judge to accept it. It could be seen from the cross-examination that it was a contestable fact whether or not, in the absence of measurement, any conclusions could be made, one way or the other, as to the probable exceeding of the respirable silica concentration levels in the breathing zone of someone working at Dasreef. If this were to be contested, someone in the position of Mr Rogers could have assisted in the resolution of the factual contest. He appeared to have relevant expertise. 56 It is not to the point that the precise terms of Mr Rogers' engagement and instructions were not in evidence. There was available to Dasreef a person whose expertise would have been relevant to any contesting of Dr Basden's opinion. In those circumstances, unless there were some explanation about why Mr Rogers was not called, it was a legitimate conclusion to be drawn by the primary judge that his evidence would not have assisted Dasreef in that regard. That is to say no more than Dasreef did not call any evidence from anyone in the same field as Dr Basden to contradict him. The primary judge was entitled then to act more confidently on Dr Basden's opinion.

The asserted failure of the primary judge to make findings as to the proportion of Mr Hawchar's total employment exposure attributable to so-called non-negligent exposure 57 Dasreef submitted that because his Honour treated the silicosis as divisible as between the Lebanon exposure, the weekend exposure and the Dasreef work exposure, he should have further divided up the 20/23 proportion attributable to the Dasreef employment by reference by giving credit for the so-called non-negligent exposure. 58 I do not agree. First, this is a question of fact. There is no legal principle requiring the primary judge to give credit in the way suggested. Secondly, whilst it can be expected that Mr Hawchar would have undergone some exposure to silica dust if Dasreef had not been negligent, there was no evidence as to what that was and the primary judge approached the matter on the basis that, factually, all Mr Hawchar's exposure at Dasreef's premises was through the negligence of Dasreef. Given the lack of a clear factual basis compelling a different approach, there can be no argument with that approach in this Court. 59 I see no error of law in this respect. 60 The substantive grounds of appeal therefore fail.

Costs 61 There was debate about the need for Dasreef to seek leave to appeal on the question of costs if (as in my view should be the case) the substantive grounds of appeal fail. Wheeler v Somerfield [1966] 2 QB 94 is authority for the proposition that an appeal which contains bona fide substantive grounds, which fail, as well as grounds relating to costs, is not an appeal as to costs alone. Wheeler has been applied in relation to the Supreme Court Act 1970 (NSW) s 101(2)(c): Tyco Australia Pty Ltd v Optus Networks Pty Ltd [2004] NSWCA 333 at [100]. The relevant provision here, the DDT Act, s 32(4)(b), is relevantly the same as s 101(2)(c). (This is to be distinguished from the position under the Administrative Decisions Tribunal Act 1997 (NSW), s 119(1A)(c) which refers to "a decision as to costs". Under that provision leave would be required irrespective of the existence of other bona fide substantive grounds: World Best Holding Limited v Sarker [2010] NSWCA 24 at [1], [2] and [102]-[103] and McGuirk v University of New South Wales [2010] NSWCA 1.) Thus, leave was not required. 62 It is necessary to commence by saying something about the significance of the scleroderma claim and the primary judge's approach to it. 63 If (as the primary judge found) the scleroderma condition was not a defined dust disease, any damages for the causation of it would come to be assessed under the regime provided for workplace injuries under the WC Act. The primary judge made detailed findings as to the causal relationship between Dasreef's breach of duty, Mr Hawchar's silicosis and his scleroderma: see [96]-[153] and [155] of the principal judgment. There was no complaint about any aspect of these findings. That, however, was explained by the fact that notwithstanding the apparent success of Mr Hawchar in relation to scleroderma, he sought to withdraw his claim for recovery of damages in respect of it. 64 At [168]-[170] of his reasons the primary judge described Mr Hawchar's position if, as he so found, scleroderma was not a dust disease: "[168] A problem arises because, Mr Hawchar, in the event that I find that his entitlement to damages in respect of scleroderma is governed by the Workers' Compensation Act 1987 wishes to waive this entitlement, so that he recovers no damages.

[169] He is driven to this election, if it is available, because s151G of the Act restricts the damages payable to past and future economic loss, and s151A provides that upon recovery of damages, a worker ceases to be entitled to any further compensation under the Act in respect of the injury concerned.

[170] Mr Hawchar's entitlements under the Workers Compensation Act 1987 in respect of his disease of scleroderma greatly exceed the value of his past and future economic loss. The Act requires that Dasreef make continuing weekly payments in respect of incapacity for work (s33), and that it pay the continuing cost of medical, hospital and rehabilitation treatment (s60), and the continuing cost of necessary domestic assistance (s60AA)." 65 At [171] of his reasons, the primary judge said that Mr Hawchar had not sought "to recover damages pursuant to s 151G" (that is of the WC Act). That was strictly accurate, but Mr Hawchar had sought damages in his statement of claim. 66 Mr Hawchar had not fulfilled the various procedural hurdles in the Workplace Injury Management and Workers Compensation Act 1998 (NSW) (the "WIM Act") that were required in order to pursue a workplace injury damages claim governed by the WC Act. 67 Dasreef, however, waived compliance with those requirements: see [174] of the reasons. Dasreef submitted that the consequence of this was that the Tribunal was required to award damages, whether or not Mr Hawchar desired to proceed with the claim. In other words, Dasreef sought to force Mr Hawchar to take an award of damages at common law, as modified under the WC Act. The consequences of this, as all parties were aware, was that he would be required to repay workers compensation payments already received and lose all his rights under the WC Act for future compensation under the WC Act "in exchange" for damages limited under the WC Act. 68 The primary judge refused to take this course. He effectively complied with Mr Hawchar's request and dismissed the proceedings to the extent to which they concerned the claim for damages for scleroderma. Hence order 1 set out at [1] above.

69 There was no appeal against this course taken by the primary judge. 70 Were it not for the operation of the DDT Act, s 11A such dismissal would put an end forever to any possible claim at common law for scleroderma. The primary judge, however, made an order under the DDT Act, s 11A: see order 4 at [1] above. 71 Section 11A of the DDT Act is the following terms: "11A Award of provisional damages

(1) This section applies to proceedings of the kind referred to in section 11 (1) that are brought after the commencement of this section and in which there is proved or admitted to be a chance that at some definite or indefinite time in the future the person who is suffering from the dust-related condition in respect of which the proceedings are brought ( the injured person ) will, as a result or partly as a result of the breach of duty giving rise to the cause of action, develop another dust-related condition.

(2) The Tribunal may, in accordance with the rules: (a) award damages assessed on the assumption that the injured person will not develop another dust-related condition, and

(b) award further damages at a future date if the injured person does develop another dust-related condition." 72 Ground 3 of the amended notice of appeal complained about the making of order 4. No submissions were put in support of that ground. 73 The primary judge came to the question of costs in the above context. 74 Offers of compromise (under the Dust Diseases Tribunal Regulations 2007 and a "Calderbank letter") had been made on 8 October 2008 in the sum of $500,000 clear of workers compensation payments paid to date, plus costs as agreed or taxed. The Dust Diseases Tribunal Regulations 2007, reg 88 provided that a person in Mr Hawchar's position should pay indemnity costs thereafter if he obtained an order or judgment less favourable than as contained in such a letter of offer, unless the Tribunal otherwise ordered in an exceptional case and for the avoidance of substantial injustice. 75 The primary judge concluded, correctly, that the orders were, in their terms, less favourable than the offers. Nevertheless, the primary judge concluded, at [2] of his costs judgment, that it was an exceptional case and to avoid substantial injustice to Mr Hawchar he would not award indemnity costs. 76 The primary judge set out his reasons for so concluding at [38]-[40] of the costs judgment as follows: "[38] I regard the following matters as relevant to the exercise of my discretion: (a) The rejection of the offer was reasonable in circumstances where the plaintiff renounced any claim to damages assessed pursuant to the Workers Compensation Act 1987. (b) The pleadings raised a factual contest as to whether Mr Hawchar's disease of scleroderma resulted from exposure to silica dust in the course of his employment by the defendant. (c) At the time the offer was made and refused, the defendant had served no medical opinion disputing the causation of scleroderma. (d) The plaintiff's success on that issue secured a contested order that he may claim further damages in the event that he contracts scleroderma lung. (e) The litigation has also secured the plaintiff's valuable continuing workers' compensation entitlements, without the additional expense of further litigation, which would mirror the evidence and arguments canvassed in this action. (f) Every witness both lay and expert, called in the plaintiff's case was required to rebut the pleaded defence that Mr Hawchar's silicosis was not caused by his work with the defendant. This was the pleaded issue upon which the plaintiff succeeded at trial, and in respect to which he recovered damages. The additional evidence given by the medical experts relating to the aetiology of scleroderma did not greatly increase the cost of the trial, and, in so far as it did, that increase was proportional to the advantage gained by the plaintiff. [39] I have concluded that this is an exceptional case, and, to avoid substantial injustice: I decline to order that the plaintiff pay the defendant's costs from the day following the offer of compromise. [40] In reliance upon the same considerations I decline to give effect to the Calderbank offer."

77 There are difficulties with some of his Honour's reasoning given that the scleroderma claim was dismissed. 78 The matters underlying [38(d)] were discussed by his Honour in [12]-[13] of the costs judgment as follows: "[12] Both the plaintiff's scleroderma and his silicosis (which on the evidence materially contributes to the scleroderma) create the relevant chance of developing scleroderma lung. The adverse finding that the scleroderma was caused by inhalation of silica dust in the course of the plaintiff's employment with the defendant has estopped the defendant from: (a) denying in any future workers' compensation proceedings that Mr Hawchar's scleroderma was an injury within the meaning of the Workers Compensation Act 1987 , that is, a disease contracted by him in the course of his employment to which the employment was a contributing factor ; and, (b) denying in any future claim for damages for scleroderma lung that that condition developed as a result, or partly as a result of, the breach of duty which gave rise to the successful action for damages for silicosis.

[13] The finding on causation ' necessarily established…the legal foundation' for the order that further damages may be made with respect to scleroderma lung ( Blair v Curran (1939) 62 CLR 464)." 79 With respect, this reasoning is incorrect. The scleroderma claim was dismissed. The findings in relation to scleroderma were obiter dicta and were not necessary findings in relation to any order that was made. Mr Hawchar will not have the benefit of issue estoppels in future litigation, other than by reference to his silicosis and to the making of the order under s 11A. Mr Hawchar was entitled to an order under s 11A which may be of utility to him in due course. In a limited way there were issue estoppels concerning the order pursuant to this provision. The making of the order under s 11A would bind the parties in the future as to the existence of the preconditions for the operation of the section: that it had been proved that there was a chance that at some time in the future Mr Hawchar would develop another dust related condition as a result or partly as a result of Dasreef's breach of duty. Such an order, whether interlocutory or final is of a character capable of creating estoppels: K R Handley, Spencer Bower and Handley: Res Judicata (4th Ed, LexisNexis) at [5.31]. However, it is not correct to say, as his Honour did, that Mr Hawchar had an advantage from the running of the case by reason of issue estoppels on the causal relationship between Dasreef's breach of duty, Mr Hawchar's silicosis and his scleroderma, beyond what was necessary to establish the preconditions of the making of the order under s 11A. On appeal, no wider notion of issue estoppel was pressed by Mr Hawchar. 80 Nevertheless, there were powerful reasons for his Honour's discretion being exercised in the way it was. Not least of these reasons was the fact that acceptance of the offer would have led to a consequence in relation to the WC Act of significant detriment to Mr Hawchar. It was perfectly understandable that he would reject the offers. It is unnecessary to explain the comparative worth of the two regimes in detail. It is sufficient to note that the correspondence of the solicitors and the conduct of the parties in the litigation reflect an appreciation of the position. Though the words of the regulation were satisfied in that the offers, in their terms, were better than the order, looked at in the broad, Mr Hawchar would have been significantly worse off by accepting the offer than he was by refusing it and retaining his workers compensation rights. Such could not legitimately be disputed. It was the reason why Dasreef was so eager to waive all its rights to have Mr Hawchar gain the "benefit" of damages under the WC Act regime. The importance of the jurisdictional fact (as to whether his scleroderma was a dust disease) placed him in peril of claiming or not claiming damages for that condition. 81 Dasreef sought to amend its notice of appeal by adding a ground which complained about [38(a)] of the costs judgment in the following terms: "To the extent that the trial judge's statements that the plaintiff 'renounced any claim to work injury damages' (at [38 (a)]) and that the defendant knew this (at [47]) represented findings of fact as to the parties' intentions and knowledge at relevant times for the purpose of the exercise of the costs discretion, such findings of fact were not reasonably open on the evidence." The amendment was ultimately not opposed.

82 Paragraphs 46 and 47 of the costs judgment were in the following terms: "[46] The plaintiff's workers' compensation rights in respect of scleroderma were always more valuable than any damages awarded pursuant to the Workplace Injury Management and Workers Compensation Act 1998 for the pure economic loss caused by that disease. The defendant cannot have been unaware of this fact. It explains that concession in the defendant solicitor's letter of 20 June 2008 to the plaintiff's solicitor that, notwithstanding the plaintiff's failure to comply with the procedural requirements of the Act, 'In the circumstances, we are not presently instructed to take the point relevant to the procedural competence of your client's proceedings'.

[47] I infer that the defendant well knew after this correspondence that the plaintiff's decision to take none of the procedural steps necessary, in the absence of waiver, to secure an award of damages for scleroderma pursuant to the Workplace Injury Management and Workers Compensation Act 1998 was deliberate." 83 This ground of appeal fails. The correspondence between December 2007 and October 2008 between the highly experienced solicitors (Moray & Agnew for Dasreef and Keddies for Mr Hawchar) made it clear that Moray & Agnew understood Mr Hawchar was not claiming damages for scleroderma other than on the basis that the scleroderma that he had was a dust disease. The correspondence made it plain that Mr Hawchar's claims for damages were pressed on that basis, and by clear inference only that basis. 84 There was no error in [38(a)] or [46] and [47] of the costs judgment.

85 There is, however, a legal error in the reasoning for the exercise of discretion, being the perception by the primary judge of broad ranging issue estoppels.

86 Dasreef also complained that in the primary judge's reasoning as to what was "exceptional" and "substantial injustice", its position was not taken into account in a balanced way. I do not agree. It is unnecessary to set out the totality of his Honour's reasons in the costs judgment. An important question to which his Honour directed attention was the degree of success that Mr Hawchar obtained in the running of the case. As his Honour said in [38(f)], on most of the issues in the case Mr Hawchar was successful. He lost in relation to the question of scleroderma being covered by the DDT Act regime. However, he gained the benefit of an order under s 11A, albeit not with the so-called issue estoppels found by his Honour. In circumstances where Mr Hawchar was placed at that risk by one issue and the overwhelming benefit to him of not accepting the offer, as both sides to the litigation would have appreciated, there were powerful reasons, on the facts as found, for his Honour to exercise the discretion in the way he did. 87 It is certainly the case that the s 11A order was only introduced into the litigation by amendment to the statement of claim made in May 2009 at the invitation of the primary judge after he had reserved judgment. It was not a claim made at the time Mr Hawchar rejected the offer. 88 Similar complaints were made about the refusal of the primary judge to order costs in relation to the dismissal of the scleroderma claim under the Uniform Civil Procedure Rules, r 42.20 (1). Under that provision, if the court makes an order for the dismissal of proceedings either generally or in relation to a particular cause of action or in relation to the whole or part of any claim, then unless the court otherwise orders, the plaintiff must pay the defendant's costs of the proceedings to the extent to which they have been dismissed. The primary judge, in identifying the good reason for departure, emphasised the value of the WC Act rights that would be lost by an acceptance by Mr Hawchar of damages under the modified workers compensation regime should he be unsuccessful (as he was) in his primary proposition that scleroderma was a dust disease within the meaning of the Workers Compensation (Dust Diseases) Act 1942. 89 The primary judge stated that throughout the trial Mr Hawchar's counsel maintained that the plaintiff sought no award of damages in respect of scleroderma if those damages were to be assessed pursuant to the modified common law damages regime. There was some debate about that at the appeal. I have already referred to the pre-trial correspondence. It is fair to say, that the underlining reality of the nature of what Mr Hawchar was pressing would have been clear to all who were involved in the case. That is, it was clear that unless scleroderma was a dust disease as defined it was manifestly not in Mr Hawchar's interest to press for damages for that condition. Ordinarily, that would place a plaintiff in a difficult position given that damages for personal injury are assessed once and for all. However, the plaintiff's position was ameliorated by the terms of s 11A which preserved the opportunity for later litigation. In any event, the conduct of the parties of the litigation reflected a clear awareness on both sides of the lack of utility to Mr Hawchar of a claim for damages for scleroderma unless he was correct in his submission that it was a defined dust disease. At [53] of the costs judgment the primary judge said: "[53] In determining whether the plaintiff has provided good reason for departure from an order that he pay the defendant's costs in relation to his claim for damages for scleroderma, I am entitled to look at the 'whole landscape comprising the course of the proceedings'. In this regard I take into account the conduct of the defendant which belatedly put in issue the medical basis upon which the plaintiff's entitlement to workers' compensation benefits depended, the overall result achieved by the plaintiff in recovering damages and preserving those rights, the success of the plaintiff in establishing a contingent right to damages for scleroderma lung, and the relatively modest increase in the costs of the trial occasioned by the ventilation of the scleroderma issue in addition to the silicosis issue upon which the plaintiff succeeded. I have concluded that these circumstances justify departure from an order in accordance with the rule."

90 These are legitimate considerations for the exercise of discretion under UCPR, r 42.20 (1). They do not, in my view, reflect any misapprehension of the proper scope of the discretion. 91 The primary judge was of the view that Dasreef should pay the costs incurred in the ventilation of the medical issues in the course of the trial. However, his Honour was of the view that the assessment of damages at common law in respect of scleroderma was clearly separable. In these circumstances, he felt it appropriate that Mr Hawchar should pay such costs as were incurred by Dasreef in obtaining reports from a forensic accountant and from the occupational therapist: see [55]-[56]. 92 His Honour also found it appropriate that the plaintiff should pay the defendant's costs incurred in the preparation of written submissions upon the medico-legal question whether scleroderma was a dust disease and upon the assessment of damages in the event that the plaintiff succeeded in his claim for common law damages for scleroderma. 93 The primary judge then said at [59]: "[59] The plaintiff recovered a modest verdict, which should not be excessively depleted by the liability to pay costs the quantum of which he could not control. The costs orders in the defendant's favour should not reduce his damages below $100,000." This led to the order numbered 7 ([1] above) which, in terms, gave effect to the primary judge's express desire in [59] to ensure that the defendant should not have damages reduced below $100,000. 94 Complaint is made about this capping on the basis that it reflected the taking into account of an arbitrary and extraneous consideration beyond that which was proper in awarding costs. 95 The terms of [59] tend to indicate that the primary judge was influenced by a desire to see Mr Hawchar take $100,000 from the litigation, irrespective of the costs to which Dasreef might legitimately be entitled under the balance of his reasons. Such an approach would see Dasreef's entitlements to costs (as found by his Honour) limited by a view that the plaintiff should have a verdict of an arbitrarily chosen sum. If this is what the primary judge did, it reveals an error of approach. 96 Paragraph 59 should, of course, be read in the light of the whole of the costs judgment. The primary judge was of the view that there was only a modest increase in the costs of the trial occasioned by the ventilation of the scleroderma issue: see [53] of the costs judgment. It may be that his Honour concluded that a reasonable assessment of those costs was something in the order that he identified. No attempt was made before us to demonstrate the level of costs in the case by reference to the division of responsibility for issues otherwise made by his Honour. 97 Dasreef is either entitled to some costs or not. Those costs could be assessed or limited by the judge by reference to relevant considerations such as the matters in [53] of the costs judgment. His Honour could also have regard to notions of proportionality and reasonableness of the parties' conduct in how the case was run in assessing what, in all the circumstances, was an appropriate sum to award for costs: see in particular, the Civil Procedure Act 2005 (NSW), s 60. But an arbitrary and isolated view as to how much Mr Hawchar should take away "in his hand" would be, in my view, a consideration foreign to the exercise of the power as to costs. 98 I am, however, unclear as to what his Honour has done in that regard. Given, if I may say so respectfully, this lack of clarity concerning the last part of his Honour's costs judgment and in the light of the error of principle in relation to the question of issue estoppel, to which I have earlier referred and which was important to his Honour's reasoning on costs otherwise, I would set aside the costs orders and remit them to the primary judge for reconsideration. I would hear the parties on costs in the appeal. 99 The orders that I would make are:

2. Set aside orders 5, 6 and 7 made by the Dust Diseases Tribunal on 15 July 2009 and contained in the form of orders signed by the Registrar of the Dust Diseases Tribunal on 25 September 2009.

3. Remit the question of costs to the Dust Diseases Tribunal for reconsideration.

4. The parties file submissions of no more than two pages on costs of the appeal within 14 days. 100 BASTEN JA: I agree with Allsop P. 101 CAMPBELL JA: I agree with the orders proposed by Allsop P and with his Honour's reasons. **********

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