I refer to my earlier posting by way of the facts and background. Of interest, is Fraser JA’s judgment with whom the court agreed, regarding s.9 of the Civil Liability Act 2003 and the expression “not insignificant” in the context of the common law threshold of “not far-fetched or fanciful”, together with s.31 (concurrent wrongdoer).
 In Wyong Shire Council v Shirt 28 Mason J explained that his analysis concerned
“foreseeability in the context of breach of duty, the concept of foreseeability in connexion with the existence of the duty of care involving a more generalized enquiry.”29 Similarly, in Vairy v Wyong Shire Council30 Gummow J referred to Glass JA‘s observation in Shirt v Wyong Shire Council31 that “… the existence or non-existence of a duty of care fell to be considered at ‘a higher level of abstraction’ than some factual considerations which were entirely relevant to the breach question…” and observed that “…in respect of breach, the close attention required to the totality of the circumstances by what has become known as the ―Shirt calculus” propounded by Mason J32 made good the distinction which Glass JA had drawn respecting levels of abstraction in dealing with duty and breach questions.” It follows that there was no necessary incongruity between the appellants’ concession at trial that a duty of care was owed and their contention that the duty was not breached because the relevant risk was not foreseeable.
 The present issue relates to breach, not duty. In that respect, the Act provides:
“9. General principles
(1) A person does not breach a duty to take precautions against a risk of harm unless –
(a) the risk was foreseeable (that is, it is a risk of which the person knew or ought reasonably to have known); and
(b) the risk was not insignificant; and
(c) in the circumstances, a reasonable person in the position of the person would have taken the precautions.
(2) In deciding whether a reasonable person would have taken precautions against a risk of harm, the court is to consider the following (among other relevant things) –
(a) the probability that the harm would occur if care were not taken;
(b) the likely seriousness of the harm;
(c) the burden of taking precautions to avoid the risk of harm;
(d) the social utility of the activity that creates the risk of harm.
10 Other principles
In a proceeding relating to liability for breach of duty
happening on or after 2 December 2002 –
(a) the burden of taking precautions to avoid a risk of harm includes the burden of taking precautions to avoid similar risks of harm for which the person may be responsible; and
(b) the fact that a risk of harm could have been avoided by doing something in a different way does not of itself give rise to or affect liability for the way in which the thing was done; and
(c) the subsequent taking of action that would (had the action been taken earlier) have avoided a risk of harm does not of itself give rise to or affect liability in relation to the risk and does not of itself constitute an admission of liability in connection with the risk.”
 For claims of the present kind, the considerations to which the plurality referred in Burnie Port Authority v General Jones Pty Ltd33 as justifying variations in the degree of care required to meet the standard of reasonable care are now reflected in s 9(1)(c) and, particularly, ss 9(2)(a) and (d), of the Act, but it remains necessary for a plaintiff to demonstrate that the criteria in ss 9(1)(a) and (b) are fulfilled. In Adeels Palace Pty Ltd v Moubarak34 the High Court emphasised the centrality of the provisions of the very similar Civil Liability Act 2002 (NSW) to questions of breach of duty (and causation).35 It was accepted for the purposes of argument in that case that there was a risk of which the defendant knew or ought to have known36 and that the relevant risk “was not insignificant”. The question was whether a reasonable person in the position of the defendant would have taken the precautions that the plaintiffs alleged should have been taken under ss 5B(1)(c) and 5B(2), provisions which are similar to s 9(1)(c) and s 9(2) of the Act. The High Court observed that the relevant questions were to be answered, “prospectively,37 not with the wisdom of hindsight … they were to be assessed before the function [in which the plaintiffs were injured] began, not by reference to what occurred that night.” and that;
“The points to be made that are of general application are first, that whether a reasonable person would have taken precautions against a risk is to be determined prospectively, and secondly, that the answer given in any particular case turns on the facts of that case as they are proved in evidence.”38
 The Act does not codify the common law but its provisions must be applied in all cases in which they are applicable. The construction of the New South Wales provisions similar to ss 9(1)(a) and (b) of the Act was not in issue in Adeels Palace Pty Ltd v Moubarak but the question whether a risk was not insignificant and foreseeable in terms of those provisions must also be determined prospectively. The trial judge did not find otherwise, but it is in issue whether the trial judge applied the statutory criteria in finding that the appellants breached their duty of care to the respondent.
 For claims governed by the common law, Shirt settled the previous debate about the degree of probability which was required before a risk could be found to be foreseeable for the purposes of deciding whether a defendant had breached a duty of care; a foreseeable risk was one which was “not far-fetched or fanciful”. The parties’ arguments in this appeal raise the question whether the test is different for claims governed by the Act. The fact that the text of s 9(1)(b) differs from Mason J’s description itself suggests that it did change the common law for claims to which it is applicable. So much is confirmed by extrinsic evidence, which is admissible in the interpretation exercise if the provision is ambiguous or to confirm its ordinary meaning.39
 The second reading speech for the Civil Liability Bill included the following:
“The bill modifies the general law regarding breach of the duty of care owed by one person to another. The test is, however, a restatement of the common law principles identified by His Honour Mr Justice Ipp, using language considered by His Honour as being appropriate for that purpose.”40
The statement that the Bill modified the general law is confirmed by reference to the “restatement of the common law” mentioned in the second sentence. That was a reference to the September 2002 final report of a panel chaired by Ipp J.41 The Explanatory Notes for the Bill recorded that the Bill implemented relevant recommendations made in that report, subject to “pertinent submissions”42 (none of which appear to bear upon the present issue.). The presently relevant passage in the report makes it plain that the expression “not insignificant” was intended to change the effect of the equivalent element in the ―Shirt formula”. After adverting to “…a danger that Shirt may be used to justify a conclusion – on the basis that a foreseeable risk was not far-fetched or fanciful – that it was negligent to take precautions to prevent the risk materialising, and to do this without giving due weight to the other elements of the negligence calculus”,43 the report continued:
“7.15 One suggestion that has been made for dealing with this problem is to modify the formula laid down in Shirt by replacing the phrase ‘not far-fetched or fanciful’ with some phrase indicating a risk that carries a higher degree of probability of harm. … The Panel favours the phrase ‘not insignificant’. The effect of this change would be that a person could be held liable for failure to take precautions against a risk only if the risk was ‘not insignificant’. The phrase ‘not insignificant’ is intended to indicate a risk that is of a higher probability than is indicated by the phrase ‘not far-fetched or fanciful’, but not so high as might be indicated by a phrase such as ‘a substantial risk’. The choice of a double negative is deliberate. We do not intend the phrase to be a synonym for ‘significant’. ‘Significant’ is apt to indicate a higher degree of probability than we intend.”
 The respondent referred to Chesterman J’s statement in Pollard v Trude44 that the replacement in s 9(1)(b) of ―not insignificant‖ for the common law formulation of “not far-fetched or fanciful” added little in clarity. Nevertheless, the provision was designed to increase the degree of probability of harm which is required for a finding that a risk was foreseeable. I think that it did produce some slight increase in the necessary degree of probability. A far-fetched or fanciful risk is necessarily so glaringly improbable as to be insignificant, but the obverse proposition may not necessarily be true. The generality of these descriptions makes it difficult to be dogmatic about this, but the statutory language does seem to convey a different shade of meaning. The difference is a subtle one. The increase in the necessary degree of probability is not quantifiable and it might be so minor as to make no difference to the result in most cases. Nevertheless, in deciding claims to which the Act applies the ‘not insignificant’ test must be applied instead of the somewhat less demanding test of ‘not far-fetched or fanciful’.
 Did the trial judge apply the statutory criteria? The trial judge found in terms that the risk was foreseeable and, despite the absence of an express finding that the risk was ‘not insignificant’, the better view is that the trial judge applied that criterion. The trial judge did not quote s 9, but her Honour did record that the relevant principles concerning breach of duty examined by Mason J in Wyong Shire Council v Shirt 45 “are dealt with in ss 9, 10, 11 and 12 of [the Act].”46 That does not convey a misapprehension that the common law criteria relating to breach remained applicable. Nothing in the trial judge’s reasons suggests the surprising conclusion that the trial judge, having acknowledged the applicability of s 9, failed to apply its terms. The appellants’ argument that the trial judge did not apply ss 9(1)(a) and (b) in holding that a “reasonable man in the position of the defendants would have foreseen that their conduct in spraying off label concentrations of herbicides in inappropriate weather conditions involved a risk of injury to the plaintiff”47 and that “the defendants breached the duty of care they owed to the plaintiff by spraying the quantities and combinations of chemicals in the weather conditions which prevailed on 15 December 2005” 48 should not be accepted.
(e) The proportionate liability question
 In the March 2011 reasons, the trial judge held,95 that the respondent‘s claim against each appellant was unaffected by the proportionate liability provision in s 31 of the Act. The relevant sections provide:
“30 Who is a concurrent wrongdoer
(1) A concurrent wrongdoer, in relation to a claim, is a person who is 1 of 2 or more persons whose acts or omissions caused, independently of each other, the loss or damage that is the subject of the claim.
(2) For this part, it does not matter that a concurrent wrongdoer is insolvent, is being wound up, has ceased to exist or has died.
31 Proportionate liability for apportionable claims
(1) In any proceeding involving an apportionable claim—
(a) the liability of a defendant who is a concurrent wrongdoer in relation to the claim is limited to an amount reflecting that proportion of the loss or damage claimed that the court considers just and equitable having regard to the extent of the defendant‘s responsibility for the loss or damage; and
(b) judgment must not be given against the defendant for more than that amount in relation to the claim.
(2) If the proceeding involves both an apportionable claim and a claim that is not an apportionable claim—
(a) liability for the apportionable claim, to the extent it involves concurrent wrongdoers, is to be decided in accordance with this part; and
(b) liability for the other claim, and the apportionable claim to the extent it is not provided for under paragraph (a), is to be decided in accordance with the legal rules, if any, that, apart from this part, are relevant.
(3) In apportioning responsibility between defendants in a proceeding the court may have regard to the comparative responsibility of any concurrent wrongdoer who is not a party to the proceeding.
(4) This section applies to a proceeding in relation to an apportionable claim whether or not all concurrent wrongdoers are parties to the proceeding.”
 Section 31 limits the liability of a defendant only in a case in which the plaintiff is entitled to recover the same loss in an “apportionable claim” against the defendant and at least one other person. Section 28(1) provides that Pt 2 of Ch 2 applies to
“…either or both of the following claims (apportionable claim)…” The following paragraph (a) includes as an “apportionable claim” a claim for economic loss or damage to property in an action for damages arising from a breach of duty of care. The respondent’s claim was an apportionable claim of that kind. The trial judge held that the appellants’ liability was not limited by s 31 because they had not satisfied their onus of proving that the former defendants were concurrent wrongdoers, or that Baker was a concurrent wrongdoer with either of the appellants, or that each appellant was a concurrent wrongdoer with the other appellant. The appellants argued that the trial judge was wrong in holding that the onus was upon the appellants, or she was wrong in holding that the appellants had not satisfied their onus of proving that one or more of the former defendants, Baker and each of the appellants were concurrent wrongdoers.
 In relation to the onus point, the appellants argued that the plaintiff bears the onus of proving, not only all of the facts necessary for a determination that a defendant was negligent, but also the extent to which each defendant was negligent and caused or should be responsible for the plaintiff‘s loss. This was said to follow from the provision in s 12 of the Act that the onus was on the plaintiff to prove all facts relevant to causation and from the absence of any provision in Pt 2 of Ch 2 imposing the onus upon each defendant. The appellants argued that s 31 did not establish a defence but instead limited a plaintiff’s entitlement to only that part of the plaintiff’s loss which was caused by a particular defendant. Upon those bases, the appellants argued that the respondent failed to establish its claim against either appellant because the respondent did not adduce evidence which established the extent to which, if at all, the appellants were responsible for the respondent‘s loss. The appellants also argued that s 31 applied even where the defendant was the only person legally liable for an apportionable claim by the plaintiff. The essence of that argument was that the only criterion of the application of s 31 is that the defendant is a ―concurrent wrongdoer‖, the definition of which in s 30 does not require that anyone other than the defendant is legally responsible for the plaintiff‘s loss or damage.
 As was submitted for the respondent, the authorities speak with one voice in favour of the trial judge’s construction. Hammerschlag J concluded in Ucak v Avante Developments Pty Ltd96 that under the similar provisions in the Civil Liability Act 2002 (NSW) a concurrent wrongdoer was one whose acts or omissions caused the claimed damage or loss and that a defendant who asserted that a person was a current wrongdoer must prove “…the existence of a particular person; …the occurrence of an act or omission by that particular person; and … a causal connection between that occurrence and the loss that is the subject of the claim.” 97 In Dartberg Pty Ltd v Wealth Care Financial Planning Pty Ltd98 Middleton J held that if a respondent relies upon the similar provisions of Pt IVAA of the Wrongs Act 1958 (Vic), the respondent bears the onus of pleading and proving the elements of the limitation of liability. Barrett J referred to that decision and adopted the same construction of the New South Wales legislation in Reinhold v New South Wales Lotteries Corporation (No 2).99 In HSD Co Pty Ltd v Masur Financial Management Pty Ltd100 Rothman J adopted the same construction, referring to Ucak v Avante Developments and Dartberg Pty Ltd v Wealth Care Finance Planning Pty Ltd and expressing his agreement with the view expressed extrajudically by McDougall J.101
 The same construction should be adopted in relation to the Act. There are textual differences between the Act and the similar legislation in New South Wales and Victoria, but the differences are not material to this issue. The trial judge’s conclusion that “…it is for the sixth and eight defendants [the appellants] to prove that the damages should be reduced because there are concurrent wrongdoers who are liable to the plaintiff because their act or omission has caused the loss or damage”102 reflects the text of s 31. That section applies only in a case in which the defendant “is a concurrent wrongdoer in relation to the claim”(s 31(1)(a)) and therefore, only where the defendant “is 1 of 2 or more persons whose acts or omissions caused, independently of each other, the loss or damage that is the subject of the claim” (s 30(1)).103 It follows that proof that an act or omission of a person other than a defendant was an independent cause of the claimed loss or damage is necessary before any occasion arises to consider whether or how a defendant‘s liability should be limited under s 31. A plaintiff’s cause of action is complete without any evidence that there is a concurrent wrongdoer; the plaintiff is entitled to recover its proved loss in full from a defendant who is proved to be legally liable for that loss. If a defendant wishes to achieve a different result, the onus must be on the defendant to prove the necessary facts. As McDougall J explained in the paper cited earlier,104 that conclusion is also suggested by the circumstance identified by Professor McDonald in an earlier paper105 that in some cases the defendant will be in a better position than the plaintiff to identify concurrent wrongdoers, and by Kirby P’s observation in Platt v Nutt106 that “…the general rule which obtains in our courts, namely that those who assert must prove”. It is necessary to add only a reference to s 32, which was discussed in the parties’ submissions. Subsection 32(1) imposes upon a claimant an obligation to claim against every person “the claimant has reasonable grounds to believe may be liable for the loss or damage”. If a concurrent wrongdoer contends that the claimant has failed to comply with that obligation, the concurrent wrongdoer may apply under s 32(4) for orders the court considers just and equitable “on…apportionment of damages proven to have been claimable” and costs thrown away by the failure. These provisions are consistent with the trial judge‘s conclusion that the onus lay upon the appellants to prove the facts necessary for any application of the legislation.
 The appellants’ additional argument that s 31 might apply where a defendant is the only person legally liable for an apportionable claim by the plaintiff does not take into account many textual indications to the contrary. Most obviously, the word “wrongdoer” in the term “concurrent wrongdoer” implies that the defendant and another person are legally responsible for the same loss or damage. Furthermore, s 11 of the Act treats causation as comprehending not only “factual causation” but also “scope of liability”, yet the appellants’ argument construes s 30(1) as though it requires reference only to “factual causation”. It is also necessary to take into account the combined effect of the introductory words of s 31, which condition its application upon the existence of an “apportionable claim”, and the composite expression in s 31(1)(a) “the liability of a defendant who is a concurrent wrongdoer in relation to the claim…”. The relevant criterion is not that the defendant is a “concurrent wrongdoer”; the defendant must be a concurrent wrongdoer in relation to the plaintiff’s apportionable claim. That suggests that the defendant and another person or persons are liable to the plaintiff for the apportionable claim. The same conclusion is suggested by the references in ss 31(1)(a) and 31(3) to the defendant’s and any concurrent wrongdoer’s “responsibility” for the plaintiff‘s loss or damage. In analogous contexts, an apportionment of “responsibility” for loss or damage has been regarded as requiring reference, not only to the relative significance of each person’s acts or omissions in causing the plaintiff‘s loss or damage, but also to a comparison of each person’s “culpability, i.e. of the degree of departure from the standard of care of the reasonable man…”.107 Another reason for rejecting the appellants’ construction is that it would produce the remarkable result that a defendant who was liable to a plaintiff could reduce the extent of the liability by proving that the plaintiff‘s loss was partly caused by an act or omission of a different person who did not breach any obligation to the plaintiff.
28 (1980) 146 CLR 40 at 47-48.
29 (1980) 146 CLR 40 at 47.
30 (2005) 223 CLR 422 at -.
31 Shirt v Wyong Shire Council  1 NSWLR 631 at 639.
32 (1980) 146 CLR 40 at 47-48.
33 (1994) 179 CLR 520 at 554.
34 (2009) 239 CLR 420.
35 See, in particular, at , , ,  and .
36 The word ―reasonably‖ in s 9(1)(a) of the Civil Liability Act 2003 was not in the otherwise identical provision in s 5B(1)(a) of the Civil Liability Act 2002 (NSW).
37 Vairy v Wyong Shire Council (2005) 223 CLR 422 at 461-463 -.
38 (2009) 239 CLR 420 at 440 .
39 Acts Interpretation Act 1954, s 14B(1).
40 Hansard, 11 March 2003, 367 (Attorney-General and the Minister for Justice).
41 ―Final report of the review of the law of negligence‖, D Ipp, P Cane, D Sheldon, I Macintosh, Treasury Department, Commonwealth of Australia, October 2002.
42 Explanatory Notes for the Civil Liability Bill 2003.
43 Review of the Law of Negligence Final Report at 7.14.
93  QSC 220 at , , , ,  – , , .
94 Transcript 1-24.
95  QSC 33 at .
96  NSWSC 367.
97  NSWSC 367 at , .
98 (2007) 164 FCR 450 at 458 .
99  NSWSC 187 at .
100  NSWSC 1279 at -.
101 See “Proportionate Liability in Construction Litigation” (2006) 22 BCL 394.
102  QSC 33 at .
103 The respondent did not argue that any claim against the former defendants would not have been for the same loss or damage which was the subject of the respondent‘s claim against the appellants: cf Mitchell Morgan Nominees Pty Ltd & Anor v Vella & Ors  NSWCA 390 at  – . The High Court granted special leave to appeal against that decision:  HCATrans 216.
104 (2006) 22 BCL 394, at 400.
105 ―Proportionate Liability in Australia: The Devil in the Detail‖ (2005) 26 Aust Bar Review 29.
106 (1988) 12 NSWLR 231 at 238.
Brisbane Barrister – David Cormack