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Whose Justice? The Search for Principled Causation in Negligence

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About The Author

Liam Reynolds (Regular Contributor)

Liam is a second year Law student at the University of Manchester. He spent a brief time at the University of Cambridge studying social sciences before realising that anything suffixed with ‘ology’ was definitely not for him. Liam was honoured to receive three scholarships in the first year of his LLB and is looking forward to being published in the Manchester Review of Law, Crime and Ethics later this year.

Image © Blue Diamond

The law of torts revolves around righting the wrongs others have committed against us. This branch of the law concerns the rights owed by and to us from everybody else, not merely those with whom we have forged binding agreements.

For liability to be established in negligence it must be shown that the defendant owed a duty of care to the claimant, that they were in breach of that duty, and that both in fact and in law the breach of that duty was the cause of the harm suffered by the claimant. The most vexing of all these is the requirement of causation. Proving a causal link between the actions of the defendant and the damage of the claimant is key for all torts, and this is no more frustrating than in the law of negligence.

Causation in the law of torts has lost its way in the search for principle. Is there anything that can be done to save it? The rare suggestion that it should be abandoned altogether, in favour of a system where liability turns on proving the breach of duty alone, has gained little weight. In the words of Lord Hoffman:

it would be an irrational system of tort liability which did not insist upon there being some causal connection between the tortious act and the damage.

Kuwait Airways Co v Iraqi Airways Co [2002] at [127]

This article argues that the judiciary has become too claimant-friendly on vague notions of ‘public policy’, and that defendants in negligence cases (particularly complex medical cases) are now at great risk of incurring tortious liability for harm which they may not have caused at all.

The Tort of Negligence

For negligence to occur it is necessary to establish that the defendant owes the claimant a duty of care, and that in carrying out their duty they have fallen below the standard of care the law prescribes to them.

Questions of duty are relatively easy to establish. Doctors clearly owe their patient a duty of care under the Hippocratic Oath, and employers owe a duty of care to their employees by way of their contractual relationship. The general standard of care is that of ‘the man on the Clapham omnibus’, more recently formulated by Lord Steyn as a ‘traveller on the London Underground’. In other words, they are the ‘reasonable man’. The standard is higher when a defendant purports to use some kind of special skill or training in carrying out a duty (Bolam v Friern Hospital Management Committee [1975] 1 WLR 582).

This is not the end of the question. Before a remedy can be applied, the claimant must show that, both in fact and in law, the defendant’s negligent breach caused their damage.  

The ‘But For’ Test  

The basic method of establishing factual causation in the tort of negligence is the simple ‘but for’ test: can we say that, on the balance of probabilities, ‘but for’ the defendant’s negligence the claimant’s damage never would have occurred? This test is well-suited for simple cases, but suffers greatly at the slightest complexity.

The famous case demonstrating the ‘but for’ test is Barnett v Chelsea & Kensington Hospital Management Committee [1969] 1 QB 428. Mr Barnett, attended the accident and emergency department of Chelsea and Kensington hospital complaining of stomach pains and vomiting. He was sent home on the orders of the on-duty doctor and later died.

There was no doubt that the doctor had owed Mr Barnett a duty of care, and that in sending him home without examining him he had breached that duty. The problem was whether or not his breach could be said to have caused the death of Mr Barnett. Nield J concluded that, on the basis that the arsenic antidote could not have been administered in time to save Mr Barnett in any event, the necessary causal link could not be made.  

The Bonnington Castings Modification

The problems with the simple ‘but for’ test were evident even a decade before Barnett was decided, in the seminal case of Bonnington Castings v Wardlaw [1956] AC 613 (HL).

Mr Wardlaw worked around silica dust in a factory. One of the sources of this dust was not regulated and the other source of the dust was required by law to be extracted. Mr Wardlaw’s employer failed to extract the dust as they were required to do, so he was simultaneously exposed to dust which was produced negligently and dust which was produced lawfully. Mr Wardlaw brought a claim in negligence for the illness he suffered as a result of his employer’s negligence.

The problem was that the answer to the question ‘but for the defendant’s negligence, would Mr Wardlaw have suffered this harm?’ must necessarily be ‘maybe’. It could not be said on the balance of probabilities that the negligently-produced dust had caused Mr Wardlaw’s harm.

Instead, the courts reformulated the test: the claimant need only prove, where there are multiple cumulative causes, that the defendant’s negligence made a ‘material contribution’ to that injury. ‘Material’ in this sense is understood as a contribution which is ‘more than negligible’ (per Waller LJ in Bailey v Ministry of Defence [2008] EWCA Civ 883; [2009] 1 WLR 1052 at [46]).

Further Extensions: Cumulative Causes in McGhee

To complicate matters further, the ‘but for’ test received another extension in favour of claimants in 1976. In McGhee v National Coal Board [1972] UKHL 7 the claimant worked at a factory which, as a result of their work, released a lot of brick dust into the atmosphere. This in itself was not negligent. Negligence arose because the defendants did not install adequate showering facilities so that employees could remove the dust from their bodies. McGhee eventually developed dermatitis as a result of his exposure.

McGhee cycled home from work each night, which took around 30 minutes. Each working day, therefore, he was exposed to eight hours’ worth of non-tortious brick dust, and a further half an hour where the dust on his skin could be considered tortious due to his employer’s failure to provide adequate showering facilities.

In the House of Lords it was held that:

… [T]he true view is that, as a rule, when it is proved, on a balance of probabilities, that an employer has been negligent and that his negligence has materially increased the risk of his employee contracting an industrial disease, then he is liable in damages to that employee if he contracts the disease notwithstanding that the employer is not responsible for other factors which have materially contributed to the disease.

 Per Lord Salmon in McGhee v N.C.B. [Emphasis added]

The increased danger of contracting dermatitis was in itself an actionable harm in McGhee.

Far from overruling the McGhee principle, the Supreme Court endorsed it in a recent case. In Sienkiewicz v Greif Ltd [2011] UKSC 10, [2011] 2 AC 229 it was proven that the appellant’s negligence had only increased the deceased Mrs Costello’s risk of developing mesothelioma by 18%. This was held to be enough to be ‘more than negligible’ and the appeal was dismissed. (For an excellent article analysing the problems of proving causation specifically in mesothelioma cases, have a look at Sam Cuthbert’s article ‘Causation in Mesothelioma Cases: Stretching the Definition’).

It would take a colder person than I not to feel any sympathy for any of these claimants. They have all suffered because of the negligence of someone else – that is beyond dispute. But can we really say that the defendant has, as a matter of fact, caused their damage because they increased the risk? Is an 18% increase in risk really ‘more than negligible’ enough to constitute a material contribution to risk? The law needs to draw the line somewhat higher in order to do justice to defendants as well as claimants.

The Blind Baby: Discrete Causes in Wilsher

In the decade following McGhee the House of Lords was again faced by an appeal involving causation in the tort of negligence, in the form of Wilsher v Essex Area Health Authority [1988] AC 1074. Action had been brought on behalf of Martin Wilsher, a baby who was born prematurely and subsequently suffered blindness. The fact that he had been born prematurely meant there were four possible ‘natural’ causes of his blindness. The negligence of the junior doctor in giving the baby more oxygen than necessary was another potential cause of the harm suffered.

In total, there were five potential causes, and so the negligence of the doctor had only a 20% of being the true cause of the blindness. The House of Lords dismissed the appeal against the health authority, reversing the decision of the Court of Appeal which held that Wilsher was a case in line with the reasoning in McGhee. Why?

Both Bonnington and McGhee involved cumulative causes of the harm, whereas Wilsher involved discrete, separable causes. Thus the case of Wilsher essentially loops back to the original ‘but for’ test, as ‘but for’ the doctor’s negligence, on the balance of probabilities, Martin Wilsher still would have become blind.

This only muddies the water further: there are now two separate causal roads to liability where negligence is established, either on the basis of McGhee or on the basis of Wilsher. It is dubious whether the Wilsher test realistically adds anything to the but for test, or if it is merely a restatement of the test cloaked in judicial language. If so, then we are back to the position in Barnett v Chelsea, and the extensions of the test have only come about on the basis of McGhee.

Revisiting Cumulative Causes: The Fairchild Exception 

In Fairchild v Glenhaven Funeral Services [2002] UKHL 22 three appeals concerning exposure to asbestos were joined. In the Fairchild case itself, Mr Fairchild had worked for two employers who had negligently exposed him to asbestos. One of those companies had since dissolved, leaving Glenhaven as the only employer to bring a claim against. The main problem was that mesothelioma, the type of cancer caused in this case, could be caused by a single asbestos fibre. It was medically impossible to prove which employer had exposed Mr Fairchild to the triggering fibre(s). Applying the ‘but for’ test (as the Court of Appeal did) produced an ‘unjust’ result, leaving the family of Mr Fairchild (who was deceased by the time the case was ever heard in court) without any compensation.

Could Glenhaven, who potentially never caused any actionable harm whatsoever to Mr Fairchild, be held liable for the cancer which killed him?

The courts revisited McGhee and found that the material increase in risk was enough even where there were multiple tortfeasors and it was impossible to establish who was factually responsible for the harm. Glenhaven were accordingly held liable when they may never have caused the harm at all. Is this just? I would suggest not. Even on the balance of probabilities it is difficult to say that Glenhaven were the cause of the harm as no medical proof could be provided. The insolvency of Mr Fairchild’s other employer meant that proceedings could only be brought against Glenhaven, who then took the full brunt of liability for harm which they may never have inflicted. Considering this overwhelming lack of evidence to support their claim, how can it rightly be said, even on the balance of probabilities, that Fairchild was correctly decided?

If we are to say that this ‘exception’ applies whenever there is a negligent breach of duty and it is impossible to prove their case, is it really an ‘exception’ at all? 

Whose Justice? 

All of the cases which modify the ‘but for’ test require close scrutiny to ensure they do not extend causation in a way which favours either claimants or defendants. I would argue that injustice comes not from leaving a claimant who cannot prove their case without a remedy, but rather holding liable those against whom a clear case cannot be made against. Shaky grounds of ‘public policy’ seem to amount to little more than feelings of great sympathy for the claimant which, while understandable, should not replace hard proof as an avenue to recovery.

Jonathan Morgan has welcomed the open admission of references to policy in their Lordships’ decision in Fairchild, but questions why there is such little substance in the judgements in Fairchild to illuminate why these references to policy are so crucial:

‘Such a “policy” says little more than that “injured claimants should recover”, and therefore it is much too wide to be of any use in setting the boundaries of what, after all, is said to be an exceptional approach.

 Jonathan Morgan, ‘Lost Causes in the House of Lords: Fairchild v Glenhaven Funeral Service’ (2003) 66(2) MLR 277, 279.

Morgan recognises that in expanding recovery by reference to ‘policy’, the House of Lords were particularly opaque. There is little discussion in Fairchild of what such policy really consists of, which leads us to the conclusion that there is little substantive force behind the judgment beyond vague notions of justice and sympathy for the claimants. Until the judiciary provides more substantial reasoning as to what is entailed by ‘policy’, there is little reason to accept the Fairchild exception as an acceptable extension of the law. 

There are several options for reform. The simplest solution may be to broaden our ideas of what a ‘cause’ really is, and in doing so embrace the claimant-friendly approach of cases like Fairchild (see Stapleton’s article below).

A more radical solution would be to abandon causation as a lost cause. Again, this may create a more claimant-friendly system, but in doing so it would embrace principle and certainty. If the only questions were ‘was there a breach of duty and did the defendant breach that duty?’ there would certainly be more ease in the law.

The issue is perhaps now so complex that it is beyond judicial repair. Perhaps only Parliament now has the power to make this area of law manageable through primary legislation which gives clarity to both claimants and defendants in these types of proceedings. On the other hand, causation in the tort of negligence is hardly a ‘sexy’, vote-winning issue and legislative intervention is unlikely any time soon.

Unfortunately, the only realistic solution is to carry on as we are and to hope that the courts eventually look for some kind of definitive legal principles that balance the interests of both claimants and defendants. Here’s hoping.

Further Reading

James Lee, ‘Causation in Negligence: Another Fine Mess’ (2008) 24 PN 194

Jonathan Morgan, ‘Lost Chances in the House of Lords: Fairchild v Glenhaven Funeral Services’ (2003) 66(2) MLR 277

Jane Stapleton, ‘Unnecessary Causes’ (2013) 129 LQR 39

Kate Wellington, ‘Beyond Single Causative Agents: The Scope of the Fairchild Exception Post-Sienkiewicz’ (2013) 20 Torts LJ 208

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Tagged: Personal Injury, Tort Law

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