What is causation by “ material contribution ” ? How does it work?

1. What is causation by “material contribution”? How does it work? Caroline Harrison QC 21 March 2016

2. FUNDAMENTALS (1) Why does causation matter? Basic legal principle wrongdoer pays for injury which s/he causes. Do not pay merely for being careless (c.f. present state of the law?!) Burden of proof on C (c.f. effect of recent cases?!) Moral problem: who should bear risk of causal uncertainty – victim, or wrongdoer? Traditional answer is the victim. Query whether still so. Problem is where injury falls well outside scope of foreseeable risk (e.g. A&E delay & DVT)

3. FUNDAMENTALS (2) One (or ?two) means of proving causation: “but for” or “material contribution to injury” (MCI) Exception 1: “material contribution to risk” (MCR) (Fairchild) Exception 2: consent & warning cases (Chester & Montgomery) The key issues in Williams v Bermuda Hospital Board was whether MCI is also an exception to ‘but for’ causation; or a sub-set of ‘but for’ which operates in special circumstances.

4. FUNDAMENTALS (3) “…the two words ‘but for’ are shorthand. They encapsulate a principle understood by lawyers, but applied literally, or as if the words embody the entire principle, the words can mislead. They convey the impression that C’s claim must fail unless he can prove that D’s negligence was the only, or the single, or even, chronologically the last cause of his injury. [Wrong]. C is required to establish a causal link between D’s negligence and his injuries, or, in short, that his injuries were indeed consequent upn the negligence” Clough v First Choice [para.44, CA] & also, now Geraghty v Somerset Partnership NHSFT

5. MCI: HISTORY (1) Bonnington 1956. Thought to be source of MCI, but based on earlier decisions that were clearly ‘but for’ cases. Novelty was in holding D liable for 100% of condition when knew that D only caused part of it. McGhee 1973. Inference used to jump an evidential gap in onset of dermatitis. In Wilsher, HL said McGhee was orthodox law, and a legitimate evidential inference (NB: that was because there was only one possible ‘agent’ responsible for the dermatitis, viz, the brick dust, c.f. in Wilsher). However, in Fairchild in 2002, HL identified McGhee for what it truly was, which was a pure ‘increase in risk’ case.

6. MCI: HISTORY (2) Hotson 1987. Exemplifies the principle that where the outcome sued-for was likely to happen irrespective of the breach of duty, there is no claim. See also: Barnett v Chelsea; Gregg v Scott Wilsher 1988. RLF, ?whether due to excess O2. Establishes that where there are alternative, competing possible explanations for the damage, the burden remains on C to prove the actual means of injury and that this was linked to the breach of duty. Fairchild 2002. Asbestos. Multiple tortfeasors. C could not prove OBP that any individual tortfeasor had contributed to his mesothelioma. He could prove that each D’s exposure had increased his risk of injury. Special exception created.

7. MCI: HISTORY (3) Bailey 2008. ERCP for gallstones. Post-op neg resulted in C being unfit for early secondary surgery, and so was much weaker & more ill with pancreatitis by the time later surgery was performed. Her inhalation of vomit and consequential cardiac arrest & brain damage was due to her weak state, which had two contributing components: non-negligent pancreatitis & poor nursing & post-op resuscitation. C argued MCI. D argued Wilsher. C won. In their Judgment, CA undoubtedly extended the law.

8. MCI: HISTORY (4) “I would summarise the position in cumulative cause cases as follows. …[‘but for’ in either direction. Or...] In a case where medical science cannot establish the probability that “but for” an act of negligence the injury would not have happened but can establish that the contribution of the negligent cause was more than negligible, the “but for” test is modified, and the claimant will succeed”[Waller LJ, para.46 of Bailey] Approved by CA in Reaney v Univ Hosp N Staffs (2015) pressure sores case

9. Williams v bermuda HOSPITALS board [2016] UKPC 4the facts 11:17 Attends ED of King Edward VII Memorial Hospital 11:40 & 12:10 Seen by Dr Okereke 12:15 Dr Okereke says CT scan ordered 13:10 Documentation suggests CT scan ordered 15:19 First evidence of rupture 17:27 CT scan performed 18:10 Williams’ final position re negligent delay (3 hrs > rup) 19:10 Hellman J. finds negligence begins (4 hrs > rup) 19:38 CT scan reported and read by Dr Di Lullo 21:30 Surgery commences (6 hrs > rup)

10. The trial Hellman J.: Mr Williams’ appendix started to rupture at about 15:19 Breach of duty in no system of STAT scans C’s case was that surgery would have begun pre-rupture or v.soon after Hellman J.: surgery would have started within 5-6 hours of CT scan being ordered, i.e. between 17:15 and 19:10 Nobody addressed causation at judge’s breaches of duty Hellman J.: “Had the CT scan been obtained and interpreted promptly these complications might have been avoided, but I am not satisfied that they probably would have been avoided.” $2,000 damages awarded for period of delay only

11. Court of Appeal for Bermuda Appeal purely on basis of causation test applied Bailey raised for the first time Court of Appeal criticised judge’s timings nonetheless “numerous delays individually and collectively were contributing factors to the damage ultimately suffered” “The proper test of causation was … whether the breaches of duty by BHB contributed materially to the injury” Remitted for damages assessment; extra $58,000 awarded

12. Appellant’s case in Privy Council MCI is not an exception to “but for” causation, but is a particular sub-set of “but for”. In any event, even on the Bailey test, C should have failed because: No scientific uncertainty to engage “material contribution” Causation based on unsafe findings of breach Material contribution cannot apply to an indivisible injury (Atomic Vets) Material contribution cannot apply to consecutive causes, but only concurrent

13. Respondent’s case in Privy Council Material contribution applies to cumulative causes Whether injury is divisible is irrelevant Whether causes were consecutive or concurrent irrelevant Court of Appeal entitled to make an inference of material contribution

14. Privy Council judgment [32] Material contribution can apply to indivisible injuries [39] “As a matter of principle, successive events are capable of each making a material contribution to the subsequent outcome”…”sequence of events may be highly relevant in considering as a matter of fact whether a later [or earlier] event has made a material contribution” [40] “A claim will fail if the most that can be said is that the claimant’s injury is likely to have been caused by one or more of a number of disparate factors” [41] Single agent requirement? [42] Where injury caused by a process, a material contribution to process = material contribution to injury

15. Heneghan v Manchester Dry Docks [2016] EWCA Civ 86 (15/2/16) Lung cancer secondary to asbestos exposure. 6 Defs. Their exposure was 35% of his total fibres/ml years. Individual D’s exposure was between 25 to 10%. Cumulative exposure to asbestos of more than 25 fibres/ml years is enough to establish that the asbestos exposure caused the lung cancer. Questions were (i) whether Fairchild exception applied to lung cancer or limited to mesothelioma; or (ii) whether MCI applied.

16. Held [para.23]: there are three ways of establishing causation in disease cases: (a) “but for”; (b) “where the disease is caused by the cumulative effect of an agency part of which is attributable to breach of duty … and part of which involves no breach of duty, D will be liable on the ground [of MCI] (Bonnington); (c) where causation cannot be proved in either of these ways, for example because the disease is indivisible, causation may be established if it is proved that D materially increased the risk of the victim contracting the disease (the Fairchild exception) [emphasis added]

17. [para.46] MCI test is to be applied “where the court is satisfied on scientific evidence that the exposure for which D is responsible has in fact contributed to the injury. This is readily demonsted in the case of divisible injuries ... Whose severity is proportionate to the amount of exposure to the causative agent”[original emphasis] In Heneghan C therefore recovered under the Fairchild exception, but his damages were apportioned & he recovered 35% of the award that would have been appropriate for 100%.

18. Dr Sido John v Central Manchester etc. Univ Hosps NHSFT [2016] EWHC 407 (QB) (2/3/16) Brain damages secondary to fall downstairs. 3 causative components: (i) initial trauma; (ii) raised ICP until surgery to evacuate the haematoma. This had 2 components due to unavoidable, and then avoidable delay; (iii) post-operative infection infection. There was no question [para.102] but that (i) & (iii) had caused some damage. J held that negligent delay had contributed to (ii) and applied MCI. C recovered full damages. But c.f. Griffiths v Sec. State for Health [2015] EWHC 1264 (QB)

19. Summary position following williams MCI is not an exception to “but for” “The Board does not share the view of the Court of Appeal that the case involved a departure from the “but-for” test. … The fact that her vulnerability was heightened by her pancreatitis no more assisted the hospital’s case than if she had an egg shell skull” [para.47, Williams] So “but for” is the required standard for causation in law (c.f. the risk cases of McGhee, Fairchild et al).

20. BUT, THE BAILEY PARADOX REMAINS “But For” means a necessary, but not necessarily the sole or even the latest factual occurrence which ultimately results in injury (e.g. Clough v First Choice). But it must be a necessary condition (i.e. without that fact, the injury would not have happened). If you can prove OBP that a breach contributed to a cumulative injurious process, but you can’t show that the breach was a necessary condition, how can you have satisfied “but for”? Does the Bailey threshold condition of scientific impossibility still apply? If so, how is that different from causal uncertainty? If so, how can ‘but for’ be satisfied?

21. THE BAILEY PARADOX The effect of Williams might appear to be that there is a ‘presumption’ in favour of causation, where you can show only a contribution to a cumulative process (c.f. Tahir). But that would effectively reverse the burden of proof, and there can be no doubt but that that is bad law! So maybe there is still room for argument?

22. (2) Temporal synchronicity This has been answered, any contribution to a cumulative process will do, whenever it occurs. This was important only if MCI was an exception to ‘but for’. If ‘but for’ applies, then you wouldn’t need to describe something as a ‘material contribution’except in situations where the contributing factor(s) are occurring at the same time. This is because whatever vulnerability existed at the time of the breach, you can say that ‘but for’ the breach, the damage would not have occurred. In practice however, the Bailey paradox remains.

23. UNANSWERED QUESTIONS (3): Is MCI limited only to single-agent cumulative processes [para.42]? If it is, then what about the following? What is a process? No injury would occur without a combination of factors (you can’t die without having been alive!). Could the speeding, dangerously overloaded motorcycle Canadian case of Clements v Clements be re-categorised as a process? Suicide? (Baker, Geraghty) What is a single-agent? It is usually obvious in industrial exposure cases, but what about synergistic different agents (e.g. hypoglycaemia & hypoxia)? Sido John says not limited to single agent [para.97] Problem would be avoided if you apply “but for” strictly.

24. UNANSWERED QUESTIONS (4): The Board did not explicitly address the conflict of appellate authority (Atomic Vets c.f. Sienkiewicz) as to whether MCI applies only to divisible injuries. It appears the Board favours application to all injuries [para.31], which is ok so long as ‘but for’ is strictly applied, because the breach is a necessary condition for the injury. But if a breach merely increases an existing risk, then full damages for an indivisible injury breaches the compensatory principle. CA in Heneghan suggests applies only to divisible injuries. Probably something only the Supreme Court could resolve.

25. HOW SHOULD YOU ANALYSE & PREPARE YOUR CASE? Worth remembering that P’s case at trial was run on the basis that he should have been in theatre before his appendix ruptured, and D’s case was it had already ruptured before he was in the ED. The findings at trial were not really considered or addressed by the experts, and Bailey was not argued until the CA. Claimants will want to categorise every outcome as the result of a cumulative process to which the breach has made some (factual) contribution. This may mean ‘zooming out’ from precise pathologies, and trying to encompass a much broader picture (life causes death!).

26. CASE PREPARATION (2) There may be an incentive for Claimants & their experts to say the ‘but for’ test can’t be satisfied (at least this will always be pleaded in the alternative – but no change there), but can infer a contribution. E.g. delay cases. Under Williams Mr Gregg would have recovered in Gregg v Scott if he could have said it was impossible to identify the percentage difference that delay made. Judges are going to find it easier to get out the broad brush & apply thick paint over causal uncertainty, and draw ‘robust common sense inferences’.

27. CASE PREPARATION (3) Defendants should really push experts to express a balance of probability opinion. After all, the judge will in effect do that if the experts don’t, and who is in a better position to draw inferences – experts or judges? The practical effect of Williams is tantamount to a reversal of the burden of proof. This means that Defendants will have to establish a better explanation for the damage, than anything resulting from the breach.

28. CASE PREPARATION (4) Foreseeability as a factor to limit liability? If the causation test no longer works to limit recovery to those cases where it can be shown that the careless conduct has caused the damage, then perhaps the filter needs to be placed further ‘upstream’, at the point of defining the scope of the duty of care. There are v good arguments to do this, and some supportive cases (Brown v Lewisham amongst others), but the problem is the effect of Hughes v Lord Advocate & Jolley v Sutton. Defendants should always consider and plead this where appropriate, and sooner or later, this will come good.