Causation Flashcards
What is the test for causation?
The ‘but for’ test must be proved on the balance of probabilities ie that there is a more than 50% chance that the defendant’s breach caused the claimant’s loss. So, a small chance that the accident might have happened anyway does not mean that the claim will fail.
In Wilsher, the claimant was unable to prove factual causation using the ‘but for’ test. There were five equally probable causes of the claimant’s loss acting independently; only one of which was the breach. The claimant could therefore only prove that there was a 20% chance that the breach caused his loss.
* In clinical negligence, where the breach is a failure to advise on risk, the ‘but for’ test can be satisfied if the claimant can prove that they would not have had the treatment or would have deferred the treatment had they been told of the risk.
What is the material contribution test?
The material contribution test is applied to factual causation when there is more than one cause of the claimant’s loss, and the causes were acting together (cumulatively) to cause the loss. By material
contribution, the court meant a ‘more than negligible’ contribution to the loss.
What is the material increase in risk test?
In industrial disease single agency cases (namely mesothelioma and lung cancer caused by asbestos), the courts might depart from the ‘but for’ test and apply the material increase in risk test.
Medical experts could demonstrate that the tortious exposure to the dust materially
increased the risk of contracting dermatitis: the longer the dust was on the claimant’s skin, the greater the risk of contracting dermatitis. The House of Lords therefore imposed liability on the defendant on the basis that their breach had materially increased the risk of the claimant’s injury.
This is arguably an easier test to satisfy than the material contribution as the claimant does not even have to prove that the breach made any actual contribution to their loss, just that it increased the chances of the claimant suffering that loss. This is perhaps why this test is only applied in very limited situations.
Although this might seem unfair to the employer, as they may have made no contribution to the mesothelioma at all, this had to be weighed against the argument that people who suffer harm due to their employers’ breach deserve to be compensated. In the case of mesothelioma, science is unable to provide the claimant with the means to ever establish factual causation using the ‘but for’ test (unless the claimant worked for only one employer who exposed them to asbestos, which is rare)
The material increase in risk test is applicable only to industrial disease, single agency cases. Single agency means that there is only one causal agent (eg the dust In McGhee and Fairchild). The medical evidence just could not prove that it was the tortious dust that caused or even contributed to the injuries
What is the loss of chance argument?
A child fell from a tree and broke his leg. The hospital was negligent in its treatment and the child was left paralysed. However, medical evidence indicated that there was a 75% risk that the broken leg would have left the claimant paralysed even without the negligent treatment. The ‘but for’ test
therefore failed. Instead, the claimant argued ‘loss of chance’ ie that he had lost a 25% chance of recovery due to
the defendant’s negligence and should be awarded 25% of his losses. The House of Lords rejected this argument. The reality of the situation was that the child was most likely paralysed by the original fall.
Although the ‘loss of chance’ argument does not seem to apply to medical negligence or personal injury cases, the courts have allowed the test in cases involving pure economic loss. In Allied Maples Group v Simmons & Simmons [1995] 1 WLR 1602 (CA), the claimant lost the chance to
negotiate a clause in a contract as a result of the solicitor’s failure to advise. Causation was successful as the claimant proved that there was a real and substantial chance that the seller would have agreed to the clause.
What is apportionment?
Apportionment is a calculation to apply once factual causation has been established. Where there are multiple tortious factors which are known to have caused part of the loss, the courts apportion liability between the defendants in a way that produces a practical result, providing compensation to the claimant while recognising the respective fault of the defendants.
The claimant crossed the road at a pelican crossing when the lights were red for
pedestrians. The first defendant driver collided with him and the claimant was thrown from the bonnet of that car into the road, where he was run over by a car driven by the second defendant. Both defendants had been negligent, and the claimant was equally at fault. It was impossible to say which of the two collisions had actually caused the injuries, or to what extent each had contributed.
Held: each defendant was responsible for 25% of the claimant’s losses (50% of the claimant’s losses were not recoverable, representing the claimant’s own negligence).
However, note that in mesothelioma cases, under s 3 of the Compensation Act 2006, defendants are jointly and severally liable. This means that any or all of the negligent employers who exposed the claimant to asbestos will be liable to the claimant for the whole sum of damages, but they can recover contributions from each other if necessary, to make the distribution of the loss fair.
How does apportionment work when there are multiple sufficient causes?
In cases such as Bonnington, the claimant suffered one loss. What happens where the claimant suffers damage as a result of the defendant’s negligence and then, some time later, a second event occurs which causes exactly the same damage, or worsens the damage already caused? In
these situations, the events are not linked and there are two or more distinct losses that can be attributable to distinct causes. There is more than one defendant each of whom pass the ‘but for’ test, but one action comes after the other (or if the later action is non-tortious, it has caused the subsequent harm). Is the original tortfeasor responsible for the loss caused by the other?
Key case: Performance Cars v Abraham [1962] 1 QB 33
Facts: A third party negligently collided with the claimant’s Rolls Royce. The Rolls required a respray to remedy it. Two weeks later, a second collision between the same Rolls Royce and a different car, driven by the defendant, caused similar damage which also required a respray to repair it.
Held: As the requirement for a respray already existed before the second collision, there was effectively no damage arising from the second collision.
Key case: Baker v Willoughby [1970] AC 467
Facts: Due to the defendant’s negligence, the claimant suffered a leg injury (pain and stiffness). Subsequently, the claimant was shot in a robbery and his injured leg had to be amputated. The robbers could not be found.
Held: First defendant should continue to be liable for the original injuries to the leg, beyond the time of robbery (even though he no longer had pain and stiffness). The intervening tortfeasor (robber) should compensate for any additional losses caused.
Key case: Jobling v Associated Dairies [1982] AC 794
Facts: Due to the defendant’s negligence, the claimant injured their back and as a result suffered reduced earnings. Some time later, the claimant suffered a further back injury (non-tortious) arising from an illness unconnected to the accident. He was unable to work at all.
Held: the defendant’s liability ceased at the point that the further back injury developed. He did not have to compensate the claimant for the ‘vicissitudes of life’.
What are the three main types of novus actus interveniens?
- Acts of God break the chain of causation if they are exceptional natural events.
- Acts of third parties break the chain of causation if they are highly unforeseeable.
If the act of third party is medical treatment, this will only break the chain of causation if it is so gross and egregious as to be unforeseeable. - Acts of claimant break the chain of causation if they are highly unreasonable. It is rare for the claimant’s unreasonable behaviour to break the chain of causation as this would normally be dealt with under the defence of contributory negligence.
