Causation

Question 1

How is causation provded?

Answer 1

Factual causation: link between breach and damage
Legal causation: considering if there are grounds upon which the ground should be broken

Question 2

What is factual causation? What is the probability?

Answer 2

The ‘but for’ test: on the balance of probabilities, but for D’s breach of duty, would C have suffered their loss at that time in that way?

• If no = factual causation satisfied; C would not have suffered their loss were it not for D’s breach
• If yes = factual causation not satisfied and D not liable

Balance of probabilities = more than a 50% chance

Barnett - C died of arsenic poisoning after drinking poisoned tea and doctor failed to carry out proper examination - but evidence showed he would have died even if doctor examined him - claim failed on causation, C would have died at that time and in that way anyway

Question 3

What if breach is one of several causes and C cannot prove there is over a 50% chance that D’s breach caused the loss?

Answer 3

Where C cannot prove that ‘but for’ D’s breach (over 50% chance), they would have suffered loss - factual causation not satisfied

Wilsher v Essex - baby born prematurely and blindness could have been caused by 5 different factors (only 1 of which - excess oxygen - was tortious), evidence showed that one factor was solely responsible for this - C had to establish that it was more likely than not (more than 50% chance) that blindness caused by breach rather than other factor, but C could only prove 20% chance so claim failed

Question 4

How does factual causation work in clinical negligence where breach is a failure to advise on risks?

Answer 4

Where the breach is a faiure to advise on risk, the but for test satisfied if C can provde on balance of probabilities they would not have had the operation or deferred to later date

Chester - surgeon failed to disclose to C the very small risk of paralysis resulting from surgery - operation resulted in paralysis in leg

Question 5

What test is applied where there is more than one cause of the C’s loss, and the causes are acting together (cumulatively) to cause the loss?

Acting together rather than 1 of several potential causes

Answer 5

The material contribution test

Cf Wilsher v Essex - evidence concluded only one cause alone caused the loss

Question 6

What is the material contribution test? If satisfied, what is D liable for?

Multiple causes operate together + but for cannot be satisfied

Answer 6

If D’s breach could be proved to have materially contributed , D liable for all loss (in absence of ‘but for’)

Exceptional circumstance where but for does not work/produces uncertain

E.g. Bailey v MOD - C choked on own vomit causing brain damage due to weakness caused by 1) progression of her condition (non-tortious) and 2) the negligent lack of care by D (tortious) - medical experts could not say that ‘but for’ negligent treatment she would not have suffered weakness and subsequent brain damage but could prove that negligent treatment made a material contribution to her brain damage and claim succeeded

Question 7

What does ‘materially contributed’ mean (i.e. how much must it contribute)? How much loss can a D be liable for if they materially contribute?

Answer 7

• More than negligible
• Can be liable for all the loss

Bonnington - C sued employers for negligence for respiratory disease caused by exposure to dust at work, some of which was non-tortious (natural consequence of work being carried out) and some tortious; operated together to produce disease - C could not satisfy but for - if D’s contribution had been more than negligible, D could be liable for all loss

Question 8

Does material contribution test apply only to things that happen at the same time?

Answer 8

No! Applies to both…

• Sequential cumulative cases e.g. C has fall and suffers head injury, then receives negligent treatment - gets brain damage
• Simultaneous cumulative cases - causes operating at the same time e.g. Bailey

Question 9

What is the material increase in risk test?

I.e. when can liability be imposed?

Answer 9

Liability can be imposed where D’s breach materially increases the risk of C’s injury (contribution is greater than de minimus)

E.g. McGhee C contracted dermatitis from exposure to brick dust during work hours (non-tortious) and during cycle journey home after work as a result of lack of washing facilities (tortious). Could not prove which caused it (but for not satisfied) or that they had operated together as it could have been all non-tortious (material contribution not satisfied) - but could show that tortious exposure materially increased risk of contracting dermatitis (longer dust was on C’s skin, the greater the risk of contracting dermatitis)

Question 10

How does the material increase in risk test work? What contribution must C prove?

Answer 10

C does not have to prove that breach made any actual contribution just that it increased chances

I.e. was not a cumulative

Fairchild - C worked for several employers through 1960s and all exposed him to asbestos; developed mesothelioma 25 years later - evidence could not determine whether disease caused by cumulative exposure over time or single asbestos fibre - HOL applied material increase in risk test to show D had materially increased risk of contracting

Question 11

Why would the material increase in risk test be applied over material contribution test? When does actual contribution need to be shown?

I.e. differences in the case law?

Answer 11

• Material increase in risk = where evidence cannot establish that loss was a result of cumulative conditions (i.e. tortious and non-tortious dust; could have been caused by all non-tortious) - do not need to show actual contribution
• Material contribution = where it is confirmed that conditions are working together to cause the loss; it is cumulative - need to show actual contribution

Question 12

When does the material increase in risk test apply? How will multiple employers be liable?

Answer 12

• Industrial diseases only
• Single agency cases (only one ‘causal agent’ e.g. dust)
• Can be jointly and severally for multiple employers over years (where impossible to tell)

Basically exclusive to mesothelioma cases/lung cancers from asbestos

Question 13

Why would the material increase in risk test not apply to a situation like Wilsher v Essex?

Where there are 5 potential causes

Answer 13

This is not a single agency case (like dust), and had five equally probable causes

This is what separates material increase in risk test from the rest

Question 14

Can loss of chance be argued for factual causation?

E.g. child falls from tree and breaks leg, hospital is negligent in treatment and leavesd child paralysed, but medical evidence suggests there was a 75% risk that broken leg would have left C paraysed even without treatment so but for fails - but can C argue for the loss of a 25% chance of recovery?

Answer 14

Not in medical negligence, but can be in pure economic loss where there is a real and substantial chance

Allied Maples - C lost chance to negotiate clause in contract as a result of solicitor’s failure to advise - C proved there was a real and substantial chance that seller would have agred to clause

Question 15

How great must D’s contribution be for?:
1. Material contribution test
2. Material increase in risk test

Answer 15

1. More than negligible
2. More than de minimis

Question 16

Summary for factual causation

Answer 16

Question 17

What is apportionment re factual causation?

How is liability apportioned?

Answer 17

Calculation to apply once factual causation established - courts apportion liability between Ds to produce practical result

Compensation to C + recognition of respective fault of Ds

Fitzgerald - both Ds crashed into C and equally negligent, but impossible to say which collission caused injury and to what extent. Each D responsible for 25% of C’s losses (50% C’s own negligence)

Question 18

Does apportionment happen in mesothelioma cases?

Answer 18

Ds are jointly and severally liably under Compensation Act

Can recover contributions from each other

Question 19

What does multiple sufficient causes mean?

I.e. what is the sequence of events

Answer 19

Where C suffers damage as a result of D’s negligence and then a second event causing same damage or worsens existing; events not linked and two or more distinct losses attributable

More than 1 D each pass but for but one action comes after other

Question 20

How does apportionment work if the second D causes no additional damage to already existing damage?

Performance Cars - TP negligently collided with C’s car which required a respray, two weeks later a second collission driven by D caused similar damage requiring respray

Answer 20

Not liable

Performance Cars - as requirement for respray already existed before second collision, there was effectively no damage arising from second collision

Question 21

How does apportionment work if the second event is tortious?

Baker - C suffered leg injury due do D’s negligence, C then shot in robbery and injured leg had to be amputated

Answer 21

D liable for original damage past second event, second D liable for additional damage

May be confined to own facts (robbers could not be found)

Baker - D continues to be liable for original injuries to leg beyond time of robbery and intervening tortfeasor (robber) should compensate for additional losses caused

Question 22

How does apportionment work if the second even was naturally occuring?

Jobling - D’s negligence injured C’s back and C suffered reduced earnings, C’s back then injured further by illness unconnected to accident

Answer 22

D liable only for damage up to natural event

Jobling - D’s liability ceased at point that further back injury developed - did not have to compensate for ‘vicissitudes of life’

Question 23

What is legal causation?

Answer 23

Considering whether there are any grounds upon which link should be regarded as having been broken

Novus actus interveniens

Question 24

What are the three types of novus actus interveniens?

Answer 24

• Acts of God
• Acts of third parties
• Acts of C

Question 25

When will acts of God/natural events break chain of causation?

Answer 25

If there is some exceptional natural event e.g. struck by lightning, onset of disease

Not foreseeable

Carslogie - C’s vessel damaged in collision with D’s ship for which D admitted liability, C’s ship suffered heavy storm damage en route to repair (reparis took way longer) - D liable for damage from collision but storm waas a novus actus interveniens

Question 26

When will acts of third parties break chain of causation?

Answer 26

If the act of a TP is highly unforeseeable (as a result of D’s negligence)

Kingtlety - D caused road traffic accident and then police negligently handled traffic control following, leading to a C being injured (had been ordered to travel down tunnel against flow of traffic) - police’s actions highly unforeseeable

Question 27

Will negligent medical treatment break the chain of causation?

Answer 27

Only if treatment is so gross and egregious as to be unforeseeable

Can be serious but not meet degree/unusualness needed

Wright - negligent failure to refer made C suffer permanent hip injury and then suffered negligent treatment at hospital - negligence still not egregious enough

Question 28

When will acts of the C break chain of causation?

I.e. C does something causing further harm

Answer 28

If they do an act which is highly unreasonable

Rare - normally dealt with under contributory negligence

McKew - C suffers leg injury due to D’s negligence resulting in impaired mobility and later descended staircase without handrail; broke ankle - was unreasonable and broke chain

Cf Wieland - had help descending the stairs and did not break chain

Question 29

What is the effect of a novus actus interveniens?

Answer 29

Chain of causation broken - D responsible for loss up until NAI but not after