The shifting of onus fallacy:
In many cases causation does not present a difficulty. That may be due, on occasions, more to oversight than reality.
In any case where breach of duty is proved, on account of an act or omission on the part of the defendant party involving a departure from reasonable care, causation between breach and injury often falls to be inferred, in reliance upon the well known passage in the reasons for judgment of Dixon J in Betts v Whittingslowe31:
… breach coupled with an accident of the kind that might thereby be caused is enough to justify an inference, in the absence of any sufficient reason to the contrary, that in fact the accident did occur owing to the act or omission amounting to the breach …
The issue taken up in the authorities is whether statements by McHugh J in Chappel v Hart32 and by Gaudron J in Bennett v Minister for Community Welfare33 connote a shifting of the persuasive (as opposed to evidentiary) onus to the defendant once breach of duty to address a risk is proved, and that risk eventuated and caused harm.
The intermediate appellate authorities subsequently eschewed this construction of those judicial comments, identifying the character of the Betts principle as line of reasoning, which falls to be considered, among other facts, in a determination of whether the plaintiff has discharged the persuasive onus of proving causation.
Section 12 of the Civil Liability Act, when enacted, emasculated any real prospect of such argument being sustained. However the same proposition has been taken up and dealt with by the High Court, adversely to any shifting of persuasive onus.
In Roads and Traffic Authority v Royal34, Kiefel J observed:
[144] The present state of authority does not accept the possibility of risk of injury as sufficient to prove causation. It requires that the risk eventuate. Kitto J in Jones v Dunkel said that one “does not pass from the realm of conjecture into the realm of inference” unless the facts enable a positive finding as to the existence of a specific state of affairs. Spigelman CJ pointed out in Seltsam Pty Ltd v McGuiness, with respect to an increased risk of injury, that the question is whether it did cause or materially contribute to the injury actually suffered. This enquiry is consistent with the commonsense approach required by March.
In Shire of Yakool v Walters35 the trial judge found for the plaintiff child who fell from park playground equipment into a fall area which had a solid composition rather than a required soft depth of 250 millimetres which would have cushioned the fall. Upholding this decision, the Victorian Court of Appeal predicated that it was plainly insufficient for the plaintiff to prove simply that it was “possible” that the plaintiff’s injury was caused by the defendant’s breach, but went on to find that the plaintiff had done more than that. Nettle JA observed:
[48] … Where a failure to warn results in a plaintiff adopting a course of action which exposes him or her to risk or increased risk of injury, and the risk occurs and he or she is injured, and it is probable that if warned he or she would not have adopted that course of action and hence would not have been injured, he or she is entitled to recover. But he or she is not entitled to recover if the connection between the failure to warn and the damage is so statistically improbable as not fairly to be attributable to the defendant’s omission to warn. In other words, as Spigelman CJ put it in Seltsam v McGuinness, when it is said that it is sufficient to establish that a breach of duty exposes a plaintiff to increased risk and that the risk eventuates, what is really meant is that the breach of duty has exposed the plaintiff to the increased risk and that the risk has eventuated because of the breach of duty.
A decision to similar effect, where the plaintiff succeeded, is Fitness First Australia Pty Ltd v Vittenberg.36
Intervening causes:
The enquiry occasionally reaches a point where there is alleged break in the chain of causation, due to some act of the plaintiff or a third party, that serving to deny a finding of causative liability. Proof of such break in causal nexus is usually difficult to establish, agitation often resulting in a finding of contributory negligence.
An example of an unsuccessful assertion of such a break, in circumstances of subsequent negligent causative harm by a treating medical practitioner, is Mahony v J Kruschich (Demolitions) Pty Ltd.37
Examples of a break in the causal chain are:
- AMP General Insurance Limited v RTA (NSW),38 where the deceased, injured in an accident, following a tense cross-examination upon the hearing of an application to extend the limitation period of his cause of action, suicided. It was found he psychiatrically decompensated, afresh, after the hearing. It was held, in a dependency action by the deceased’s spouse, that such suicide broke the chain of causation.
- Postnet Pty Ltd v Wood,39 where a plaintiff entrant to a nightclub was injured when he fell after exiting through a window to an awning and then a nearby building, from which he then fell.
- Lyle v Soc,40 where the deceased was injured in a minor motor vehicle accident and subsequently died after abusing and then over-dosing on prescribed pain relief medication. The Queensland decision of Lisle v Brice41 was distinguished as the injury there arose from a motor collision of greater moment.
The break in the chain of causation is sometimes expressed to have its foundation in what is described as a “free deliberate and informed”42 act or decision of the plaintiff or a third party. The decision of the High Court in Medlin v State Government Insurance Commission43 recites the jurisprudence in respect of establishing such a break in the causal nexus:
[6] For the purposes of the law of negligence, the question whether the requisite causal connection exists between a particular breach of duty and particular loss or damage is essentially one of fact to be resolved, on the probabilities, as a matter of common sense and experience … And that remains so in a case such as the present where the question of the existence of the requisite causal connection is complicated by the intervention of some act or decision of the plaintiff or a third party which constitutes a more immediate cause of the loss or damage. In such a case, the “but for” test, while retaining an important role as a negative criterion which will commonly (but not always) exclude causation if not satisfied, is inadequate as a comprehensive positive test … If, in such a case, it can be seen that the necessary causal connection would exist if the intervening act or decision be disregarded, the question of causation may often be conveniently expressed in terms of whether the intrusion of that act or decision has had the effect of breaking the chain of causation which would otherwise have existed between the breach of duty and the particular loss or damage. The ultimate question must, however, always be whether, notwithstanding the intervention of the subsequent decision, the defendant’s wrongful act or omission is, as between the plaintiff and the defendant and as a matter of common sense and experience, properly to be seen as having caused the relevant loss or damage. Indeed, in some cases, it may be potentially misleading to pose the question of causation in terms of whether an intervening act or decision has interrupted or broken a chain of causation which would otherwise have existed. An example of such a case is where the negligent act or omission was itself a direct or indirect contributing cause of the intervening act or decision. It will be seen that, on the plaintiff’s evidence, the present was such a case.
[Footnotes deleted, emphasis added]
Three examples of disposition under the Medlin jurisprudence, with a result of causal nexus being proved, are Hirst v Nominal Defendant44 (plaintiff police officer engaging in high speed chase), Blaxter v Commonwealth of Australia45 (plaintiff engaging in disabling alcohol abuse due to psychiatric condition) and Bonny Glen Pty Ltd v Country Energy46 (see below).
In Bonny Glen a fire negligently caused by the defendant electrical authority destroyed a row of pine trees on a property adjacent to the plaintiff’s property. The row constituted a dedicated windbreak for spraying of the plaintiff’s commercial orchard, the spraying necessary to inhibit pest and weed infiltration. Pending regrowth of the windbreak, the plaintiff razed the orchard. It did so on expert advice. The defendant challenged causation of the economic consequence for orchard production on the footing that it was not foreseeable or reasonable. This argument was rejected:
[48] In addressing the question whether, as a matter of common sense, the breach of duty by Country Energy was a material cause of Bonny Glen’s loss, the following matters are relevant. The windbreak was plainly advantageous to Bonny Glen, in protecting the trees, creating a micro climate and in reducing problems associated with the use of poisonous sprays; so undoubtedly the destruction of the windbreak would create problems for Bonny Glen and be likely to cause damage to Bonny Glen. The breach of duty by Country Energy thus created a problem for Bonny Glen, and in those circumstances the standard of reasonableness for Bonny Glen’s conduct should not be set too high: see Banco de Portugal v Waterlow and Sons Limited [1932] UKHL 1; [1932] AC 452 at 506. On the other hand, it should not be set too low, and in assessing reasonableness it is necessary to have regard to the interests of Country Energy as well as the interests of Bonny Glen.
[49] … [Bonny Glen’s agent] sought expert advice, which was to the effect that, because of the risk of spray drift and the risk of the commission of an offence and prosecution, Bonny Glen should not spray in the area until the windbreak was re-established; and that it therefore should remove the trees. [Bonny Glen’s agent], because of the concerns of the neighbour, the risk of spray drift and commission of an offence and prosecution, and because of the expert advice, decided to remove the trees. It was not suggested to the experts that they did not hold their opinions or give them; and the expert called by Country Energy, Mr Gordon, accepted that the question whether to continue spraying was a matter of judgment.
[50] In my opinion, it is not necessary to find on the balance of probabilities that the expert advice was correct. It was not shown to be plainly unreasonable, or even to be incorrect. In my opinion, in those circumstances, Bonny Glen did prove that its conduct was reasonable, and reasonable having regard both to its own interests and the interest of Country Energy. Accordingly, in my opinion the economic loss resulting from the removal of the trees was caused by the fire and thus caused by Country Energy’s breach of duty.
[Emphasis added]
In State Rail Authority of New South Wales v Chu47 the plaintiff suffered a temporarily disabling ankle fracture in the subject accident for which the defendant was found liable. A question arose whether further injury of a psychiatric nature, resulting from a sexual assault perpetrated upon her while she was still disabled, ought be causatively visited on the defendant.
Matthews AJA (Hodgson and Bell JJA agreeing), over-ruling the trial judge, held in the negative:
…
[52] Dealing first with the issue of causation: the appellant submitted that the trial judge overstated the evidence linking the respondent’s injury with the subsequent sexual assault. It was not her lack of mobility which principally constrained her from leaving the assailant’s room, according to the evidence. Other factors were much more significant, particularly the presence downstairs of the assailant’s parents, and the fact that the assailant had taken her wallet and telephone and she did not want to leave without them.
[53] There is considerable strength in this submission. From a factual point of view there was little evidence to support his Honour’s finding on the causation issue. It was a matter which the respondent was required to prove, and in my view the preponderance of evidence was that the assault would probably have occurred whether or not she had been injured in the fall.
[54] There were, in any event, other reasons for finding against the respondent on this issue, even if the evidence had favoured the respondent’s submissions. For the sexual assault was plainly, in my view, a novus actus interveniens which broke the chain of causation. As McHugh J said in Bennett v Minister of Community Welfare [1992] HCA 27; (1992) 176 CLR 408 at 429—430:
“The causal connexion between a defendant’s negligence and the plaintiff’s damage is negatived by the subsequent conduct of another person only when that conduct is “the free, deliberate and informed act or omission of a human being, intended to exploit the situation created by defendant”.
[55] The conduct of the respondent’s assailant was clearly a “free, deliberate and informed act.” It is questionable whether it was intended to exploit the respondent’s immobility. But it was certainly the type of conduct which would have broken the chain of causation.
[Emphasis added]
The court indicated they would also have found against the plaintiff on the basis of remoteness of damage, any sexual assault not being reasonably foreseeable.
In Zanner v Zanner48, referred to earlier, the plaintiff was the mother of the defendant. She sustained serious injuries when struck by a motor vehicle being manoeuvred by the defendant in her direction into the carport of the family home. The defendant was then aged 11 years and two months. His foot slipped from the brake onto the accelerator causing the vehicle to surge forward and collide with the plaintiff who had placed herself and was standing directly in front of the vehicle. He had successfully so manoeuvred the vehicle on about six prior occasions.
The trial judge found for the plaintiff but adjudicated contributory negligence to the extent of 50%. The primary liability finding was upheld on appeal but the contributory negligence finding was overturned and amplified to 80%.
Allsop P wrote as to causation in that case:
[12] … This case does not demand any great agonising over the application of ss 5D(1)(b) and (4). All relevant considerations that inform the content of the appropriate scope of the negligent person’s liability and responsibility point to a positive conclusion as to causation and liability here. Injury to the mother was entirely foreseeable should negligence occur. The scope of the risk of harm protected by the duty and created by the breach included injury to the mother. The injury was not coincidental to the breach. It was the direct and immediate consequence of the negligence. The son in the car ran over his mother. The content of the duty and the attenuated standard of care were directed to the exercise of care to avoid injury to the mother in the very manner that occurred. There was no intervening act of a third party or of an abnormal event. The only other causal factor was the negligence of the person (the mother) to whom the duty was owed. There is no reason why the appropriate apportionment of respective responsibility is not best allocated through contributory negligence. Common sense would attribute the mother’s injury to the negligence of her son, as well as to her own negligence in putting herself in that position.
[Emphasis added]
What this helpful analysis points up is the issue raised by Gummow and Hayne JJ in Travel Compensation Fund v Tambree49:
[45] It is now clear that there are cases in which the answer to a question of causation will differ according to the purpose for which the question is asked. As was recently emphasised in Allianz Australia Insurance Ltd v GSF Australia Pty Ltd, it is doubtful whether there is any “common sense” notion of causation which can provide a useful, still less universal, legal norm. There are, therefore, cases in which the answer to a question of causation will require examination of the purpose of a particular cause of action, or the nature and scope of the defendant’s obligation in the particular circumstances.
[46] In Allianz, McHugh J noted that considerations of legal policy may enter into the selection of those causative factors which are determinative of liability. However, to accept that proposition, as it should be, is not to adopt a quite different proposition that in any given case the ultimate issue is whether “the defendant ought to be held liable to pay damages for [the] harm [suffered]”. This approach to questions of causation taken by Ipp JA in Ruddock v Taylor was adopted by the Court of Appeal in the present case.
[Footnotes deleted, emphasis added]
Loss caused to a plaintiff by his or her own criminal activity, even if wrought by accident induced circumstances including usually psychiatrically altered disposition, ordinarily founds a severance of causal nexus.50
The Lesson:
The above recitation of principle and case examples make plain, I submit, the fact sensitive character of the causation enquiry.
Causation requires preparation and treatment as much as any other litigation issue.
In construction and development of the case theory, each pleaded result of breach of obligation ought be addressed by reference to what case adduced and (proposed) cross-examination elicited evidence is apt, together with the intellectual argument by which causal nexus is to be advocated founded on such evidence.
Such argument ought be fashioned such as to appeal to the court’s “good sense of the thing”. Elevating a possible link to one which is probable is as much a matter of commonsense based on life and legal experience as it is a matter of evidence. The question is ultimately one of fact.
Intuitively the experienced practitioner knows when, in the above process, the Rubicon of probability has been crossed, and by corollary whether he or she is shy of the same.
Conclusion:
The law is pragmatic when it comes to causation.
Historian AJP Taylor made such a point when he wrote about the causes of war:51
Wars are much like road accidents. They have a general cause and particular causes at the same time. Every road accident is caused, in the last resort, by the invention of the internal combustion engine and by men’s desire to get from one place to another. In this sense, the ‘cure’ for road accidents is to forbid motor cars. But a motorist, charged with dangerous driving, would be ill-advised if he pleaded the existence of motor cars as his sole defence. The police and courts do not weigh profound causes. They seek a specific cause for each accident — error on the part of the driver; excessive speed; drunkenness; faulty brakes; bad road surface.
It is the particular causes that require attention in proving a link between breach of obligation and subsequent event yielding damage or loss.
In this paper I have attempted to explore the limits to recovery of damages which the law imposes by the concept of causation, to recovery in common law causes of action.
Another limiting concept also exists, namely that of remoteness of damage, but again that is beyond the scope of this paper.
It ought be borne steadily in mind that causation is a question of fact entailing, potentially, “but for” and scope of liability considerations. An exceptional case will behove drilling down into more philosophical considerations of whether and why liability for the harm ought be visited on the defendant. These respective considerations have been taken up in Queensland in the Civil Liability Act and the Workers’ Compensation & Rehabilitation Act and must be considered in that order without conflation.
In adjudicating proof of causation, decided cases ought be referred to solely for the purposes of general principle, not precedent for a particular outcome merely because factual similarities exist. Each new case is fact sensitive.
In science the mere flap of a butterfly wing may well produce a surprising natural outcome. In the law, on occasions, breach of duty of care might spawn a substantial and unusual damage outcome notwithstanding a raft of other circumstances combining to contribute to that outcome.
R J Douglas S.C.
Footnotes
31. (1945) 71 CLR 637
32. (1998) 195 CLR 232
33. (1992) 176 CLR 408
34. [2008] HCA 19; see also Adeels Palace at [50] — [53]
35. [2005] VSCA 216
36. [2005] NSWCA 376
37. (1985) 156 CLR 522
38. (2001) 22 NSWCCR 247; Aust Torts Reports 81-619 (NSWCA)
39. [2002] ACTCA 5
40. [2008] WASCA 3
41. [2002] 2 QdR 168
42. Bennett v Minister of Community Welfare (1992) 176 CLR 408 at 429-430
43. (1995) 182 CLR 1
44. [2005] 2 Qd R 133;
45. [2008] NSWCA 87
46. [2009] NSWCA 26
47. [2008] NSWCA 14
48. [2010] NSWCA 343
49. (2005) 224 CLR 627
50. State Rail Authority of New South Wales v Wiegold (1991) 25 NSWLR 500; Bailey v Nominal Defendant [2004] QCA 344
51. AJP Taylor “The Origins of the Second World War” (The Folio Society, 1998) at 115-116. I am indebted to Mr Liam Kelly SC for this quote which is contained in a 2010 paper delivered by him in the BAQ/UQ Seminar Series, namely “Causation and s 82 of the Trade Practices Act” pg 18.
