Causation
1. ‘But for’ Test:
Barnett v Chelsea and Kensington Hospital Management Committee
Deceased went to A&E after unknowingly drinking tea laced with poison.
The attending doctor did not examine him but instead told him to see his GP,
and 5 hours later he died. Expert evidence indicated that even if he had been
treated, the man probably would have died.
Test = if, but for the breach, the claimant would still suffer the injury, then
causation is not established.
Burden of proof on claimant to establish causation.
Constituent element of tort.
Hypothetical exercise – has to be more than 50%.
Equal is not sufficient.
“Probably would have suffered harm” – not definitely –
balance of probabilities.
2 torts sufficient:
But for not make out but if both torts are sufficient then both liable.
e.g., two shooters shoot at the same time.
2. Material Contribution to Injury:
Bonnington Castings Ltd v Wardlaw
Couldn’t say that the defendant was the but for cause of the claimant’s
pneumoconiosis.
Not all inhalation was due to negligence, some was due to ordinary
usage and would have inhaled background dust.
BUT – can say that D made injury worse.
Therefore = material contribution to injury.
There are two types of cases:
(1) Cumulative injuries/injuries:
e.g., noise induced deafness – Baker v Quantum.
e.g., more exposure, worse condition becomes – Bonnington.
(2) Single continuous chain of events:
Williams v Bermuda Hospitals Board – injury developed
incrementally over approximately 6 hours.
Cause of injury = single continuous chain of events.
As long as D’s negligence makes a material contribution to
this chain of events.
Tricky in application – short period of time would be
different than if over two days.
What is D liable for?
Lord Phillips (obiter) in Sienkiewicz – treat D as liable only for portion of
losses in cases of cumulative injury.
BUT – in a Williams type case, D is taken to have caused (as having made a
material contribution to) the whole indivisible injury, and therefore is liable
for the full amount.
3. Material Contribution to Risk:
Fairchild v Glenhaven Funeral Services Ltd
Very different scenario.
Scientific uncertainty on all fronts – cannot work out what happened.
Problem = couldn’t make out but for test.
Couldn’t point to any single employer equally likely than another.
What are the parameters of this?
Purely for mesothelioma?
Case law has flip-flopped.
, McGhee v National Coal Board – dermatitis.
Indicates that applies beyond.
Sienkiewicz – wanted to confine only to mesothelioma.
Policy – recognised severity of mesothelioma and that
employers shouldn’t escape just because of scientific
uncertainty.
Heneghan v Manchester Dry Docks Ltd – asbestos but lung cancer.
CA held that the facts were so analogous that it would be
arbitrary not to extend the principle.
Answer = seems to apply to highly analogous situations but unlikely
to be able to expand further.
What kinds of exposure?
In Fairchild, all Ds were tortfeasors – all exposures were due to
negligence – judges seem to rationalise differently.
Lord Bingham – see this as requirement.
Lord Nicholls – hesitant to draw conditions.
Barker v Corus plc – self-employed.
Did not stop claim – not precondition.
Sienkiewicz – atmospheric
Doesn’t stop claim.
“Doubles the risk” is not the test – just material contribution
is enough.
Can be small, doesn’t have to double it.
More complainant friendly.
Concern of relying on epidemiological evidence.
Difficult to draw inferences from.
Not medical but statistical evidence – numbers
spoken about are so small that not sensible to rely on
this.
Mesothelioma is such a rare case that results may
change massively if one person added to the sample.
Adopts very minimal understanding of material contribution.
Must be a line – material = pretty low bar.
Apportionment:
Barker v Corus – widened scope of liability but put limitation on
compensation.
D liable for portion of injury that signifies contribution.
Parliament didn’t like this.
Problematic as employees had to bear burden of employers
being insolvent.
Compensation Act 2006:
Overruled Barker – Ds liable for whole.
Exceptions:
Parts of the UK that follow CL – e.g., Jersey follows
Barker.
Speaks specifically of mesothelioma.
Heneghan expanded to lung cancer – Barker
still applies.
Have ended up treating mesothelioma and lung cancer differently.
4. Failure to Warn about Risk:
Chester v Afshar – risk was not due to surgery being performed well (random) but
rather negligent failure to warn.
Lower courts – but for approach.
Found that would have had surgery three days later.
1. ‘But for’ Test:
Barnett v Chelsea and Kensington Hospital Management Committee
Deceased went to A&E after unknowingly drinking tea laced with poison.
The attending doctor did not examine him but instead told him to see his GP,
and 5 hours later he died. Expert evidence indicated that even if he had been
treated, the man probably would have died.
Test = if, but for the breach, the claimant would still suffer the injury, then
causation is not established.
Burden of proof on claimant to establish causation.
Constituent element of tort.
Hypothetical exercise – has to be more than 50%.
Equal is not sufficient.
“Probably would have suffered harm” – not definitely –
balance of probabilities.
2 torts sufficient:
But for not make out but if both torts are sufficient then both liable.
e.g., two shooters shoot at the same time.
2. Material Contribution to Injury:
Bonnington Castings Ltd v Wardlaw
Couldn’t say that the defendant was the but for cause of the claimant’s
pneumoconiosis.
Not all inhalation was due to negligence, some was due to ordinary
usage and would have inhaled background dust.
BUT – can say that D made injury worse.
Therefore = material contribution to injury.
There are two types of cases:
(1) Cumulative injuries/injuries:
e.g., noise induced deafness – Baker v Quantum.
e.g., more exposure, worse condition becomes – Bonnington.
(2) Single continuous chain of events:
Williams v Bermuda Hospitals Board – injury developed
incrementally over approximately 6 hours.
Cause of injury = single continuous chain of events.
As long as D’s negligence makes a material contribution to
this chain of events.
Tricky in application – short period of time would be
different than if over two days.
What is D liable for?
Lord Phillips (obiter) in Sienkiewicz – treat D as liable only for portion of
losses in cases of cumulative injury.
BUT – in a Williams type case, D is taken to have caused (as having made a
material contribution to) the whole indivisible injury, and therefore is liable
for the full amount.
3. Material Contribution to Risk:
Fairchild v Glenhaven Funeral Services Ltd
Very different scenario.
Scientific uncertainty on all fronts – cannot work out what happened.
Problem = couldn’t make out but for test.
Couldn’t point to any single employer equally likely than another.
What are the parameters of this?
Purely for mesothelioma?
Case law has flip-flopped.
, McGhee v National Coal Board – dermatitis.
Indicates that applies beyond.
Sienkiewicz – wanted to confine only to mesothelioma.
Policy – recognised severity of mesothelioma and that
employers shouldn’t escape just because of scientific
uncertainty.
Heneghan v Manchester Dry Docks Ltd – asbestos but lung cancer.
CA held that the facts were so analogous that it would be
arbitrary not to extend the principle.
Answer = seems to apply to highly analogous situations but unlikely
to be able to expand further.
What kinds of exposure?
In Fairchild, all Ds were tortfeasors – all exposures were due to
negligence – judges seem to rationalise differently.
Lord Bingham – see this as requirement.
Lord Nicholls – hesitant to draw conditions.
Barker v Corus plc – self-employed.
Did not stop claim – not precondition.
Sienkiewicz – atmospheric
Doesn’t stop claim.
“Doubles the risk” is not the test – just material contribution
is enough.
Can be small, doesn’t have to double it.
More complainant friendly.
Concern of relying on epidemiological evidence.
Difficult to draw inferences from.
Not medical but statistical evidence – numbers
spoken about are so small that not sensible to rely on
this.
Mesothelioma is such a rare case that results may
change massively if one person added to the sample.
Adopts very minimal understanding of material contribution.
Must be a line – material = pretty low bar.
Apportionment:
Barker v Corus – widened scope of liability but put limitation on
compensation.
D liable for portion of injury that signifies contribution.
Parliament didn’t like this.
Problematic as employees had to bear burden of employers
being insolvent.
Compensation Act 2006:
Overruled Barker – Ds liable for whole.
Exceptions:
Parts of the UK that follow CL – e.g., Jersey follows
Barker.
Speaks specifically of mesothelioma.
Heneghan expanded to lung cancer – Barker
still applies.
Have ended up treating mesothelioma and lung cancer differently.
4. Failure to Warn about Risk:
Chester v Afshar – risk was not due to surgery being performed well (random) but
rather negligent failure to warn.
Lower courts – but for approach.
Found that would have had surgery three days later.
