Understanding Thorley and Material Contribution

“Indivisible Injury” has more than one meaning so make sure you’re not at cross purposes with the judge

1. The essential facts are that the Claimant had chest pain and needed angiography (an investigation of the blood vessels to the heart). He stopped warfarin (a long term anticoagulant) on 23 April, had the angiogram on 27 April and restarted warfarin on 29 April. The next day he suffered an ischaemic stroke which has resulted in permanent and severe physical and cognitive disability.
2. There was a dispute on breach of duty as to whether the total period for which warfarin was stopped should have been 3 days rather than 6 and whether it should have been restarted earlier and at a higher dose.
3. The judge preferred the Defendant’s expert evidence on breach of duty and was entitled to. That’s not the problem.
4. On causation the Claimant’s case was that if the warfarin had been properly managed he either would not have had the stroke or alternatively, the reduced dose materially contributed to the stroke.
   
5. Again the judge preferred the Defendant’s expert evidence and found that the stroke would probably have happened anyway. I’m surprised by that conclusion (I would have thought that either the stroke would not have happened or at most it would not be possible to say) but on the face of it he was entitled to agree with the Defendant.
6. Either or both of these conclusions would have been more than enough to dispose of the claim in the Defendant’s favour but the judge insisted on addressing all issues and this took him into territory which he appears to have found tricky.

7. The most problematic part of the judgment is paragraph 147 where Soole J says this:

“On the face of it, the Court of Appeal decision in AB is binding authority that the test of material contribution has no application to a case where (as here) there is indivisible injury and one tortfeasor.”

8. He then suggests that Heneghan is also authority for this proposition but noted that the observations of the Privy Council in Williams v Bermuda, “provide support for the rival contention, in particular through the endorsement of Professor Green’s statement of ‘trite negligence law’.”

9. He bypasses the excellent analysis of Picken J in John v Manchester Soole J says “As to the very detailed discussion of the law of material contribution in John, I do not read it as dealing with this particular issue.”

10. Finally, concluding that AB and Williams are inconsistent (I don’t think they are) he says: 

“This is evidently a legal issue which is ripe for authoritative review”

11. I wonder if the problem in this case came from confusion over what ‘indivisible injury’ meant.

12. As clinical negligence practitioners know the phrase ‘indivisible injury’ means different things in different contexts:

1. 1. Death is indivisible in the sense that you cannot be only partly dead. Yet death might be the result of a number of different (cumulative) causes, of which only one is a breach of duty. Bailey is a classic example of cumulative causes leading to an indivisible injury (non-negligent pancreatitis and negligent dehydration led to weakness which meant the claimant was unable to clear her airway, she suffered cardiac arrest and hypoxic brain injury.
   2. An hypoxic brain injury might be indivisible in the sense that birth 5 minutes earlier would have resulted in a lesser insult but it is not possible to identify what level of disability the claimant would have had but for the negligent delay 5 minute delay. See Popple v Birmingham. See also John v Manchester where the Claimant would have had a brain injury even without the negligent delay in surgery but it was not possible to say how injured he would have been.
   3. Mesothelioma is indivisible in the sense that its severity does not depend on the extent of exposure to asbestos. This was the sense that ‘indivisible’ was used by Smith LJ at paragraph 150 of AB v MOD (Atomic Vets) or by Dyson MR in Heneghan v Manchester.

13. See paragraph 139 where Soole J says, “In the light of the agreed expert evidence, Ms Rodway, accepts that ischaemic stroke is an indivisible injury i.e. which either happens or does not and whose size or severity is unaffected by the dose of warfarin.”

14. I think what the Claimant meant by ‘indivisible injury’ was that it was the product of cumulative causes. I doubt very much that Ms Rodway was accepting that the stroke was indivisible in the AB/Heneghan

15. From this point on the claimant and the judge were at cross purposes and once this is understood it becomes easier to see why Soole J reached the conclusion that he did.
16. So what should the judge have done?  The correct approach to Bailey, on the basis of the judge’s actual findings (i.e. preferring the view of the Defendant’s expert that the stroke would have happened anyway) would have been:

1. 1. Would the outcome probably have been the same in any event. If ‘yes’ then claim fails. If ‘no’ or ‘can’t say on balance of probabilities’; then continue to next question.
      Answer: Yes. Claim fails.
   2. Did the breach of duty make a material i.e. more than negligible contribution to the outcome? If ‘yes’ then claim succeeds. If ‘no’ claim fails. If the answer is ‘it might have done but we don’t know’ then the claim fails because proving that a breach of duty might have made a material contribution is not sufficient.
      Answer: n/a

17. What would the correct approach have been if the judge had preferred the Claimant’s expert evidence?

1. 1. Would the outcome probably have been the same in any event. If ‘yes’ then claim fails. If ‘no’ or ‘can’t say on balance of probabilities’ then continue to next question.
      Answer: ‘No’ or ‘can’t say on balance of probabilities’ so proceed to next question.
   2. Did the breach of duty make a material i.e. more than negligible contribution to the outcome? If ‘yes’ then claim succeeds. If ‘no’ claim fails. If the answer is ‘it might have done but we don’t know’ then the claim fails because proving that a breach of duty might have made a material contribution is not sufficient.
      Answer: ‘Yes’. Claim succeeds.

18. Thorley won’t be appealed because the Claimant’s case on breach of duty was weak and because on causation the judge found that the outcome would have been the same in any event. It should not however be regarded as any sort of authority on material contribution.