1. But for test or legal causation the correct test in attributing responsibility?
Akinola Samuel Eluyefa *
In order to effectively answer this question, it is important to understand the keywords to be
used in the context of this essay. But for causation consisting of posing the question of but for
the defendant relevant act or omission, the loss or expected loss would not be sustained by
the claimant.
Hence this essay aims to put into the context how subsequent case laws have adhered to
applying to the orthodox principles of causation, 1
or applying a more evaluative and
normative policy driven analysis 2
Firstly, as regards to what was decided in Barnett v Chelsea 3
of which the courts held but for
the defendant breach in the context of failing to diagnose the defendants were suffering from
arsenic poisoning, the death would still have occurred on the balance of probabilities. Hence,
since the treatment which the doctor would have given him could not have saved him,
causation had not been established. Therefore, as regards to the casual question of whether
the but for test is sufficient for the purposes of attribution of responsibility, the case above
indicates succinctly responsibility would not be attributed if causation cannot be established.
However, critics might disagree with the analysis above with reference to what was decided
in Fairchild v Glenhaven Funeral Services Ltd 4
where the House of Lords qualified the but
for test to allow recovery in a case where it was impossible on the state of scientific evidence
to determine which one or more of several employers, all admittedly in breach of duty had
1
J Stapleton, Occam's razor reveals an orthodox basis for Chester v Afshar L.Q.R. 2006, 122(Jul), 426,427
2
R. W. Wright, Causation in Tort Law’ (1985) 73 Cal LR 1735
3
[1969] 1 QB 428
4
[2002] 3 All ER 305

2. allowed the claimant to suffer a fatal illness. Therefore, not only did Fairchild did depart from
the normal rule of causation, in the words of Bastian Zahn it could be said in Fairchild the
Hol was called to decide on the issue of alternative causation.5
with this established principle
in the context of this case applying to scenarios where there are periods of exposure to risk by
several defendants in breach of duty.
Therefore, although the traditional but for test is based on the precept that the D should not be
liable for a loss which he personally did not cause, this notion would come into conflict with
the intended aim of ensuring that a victim of a tortious conduct is fully compensated for
losses caused by fault, which is the main objective of tort law itself.
Hence the decision in Fairchild was facilitated by policy factors which dictated a departure
from the normal rule. 6 Therefore, it was not necessary to show which of defendant had
caused the injury in fact, as the medical opinion to the cause of mesothelioma is not
cumulative i.e. since it could be caused by one or many fibres, the court did conclude as
matter of fact, the injury had been caused by any defendant that materially increased the risk
of the claimants contracting mesothelioma.7
However, critics such as Gary Meggitt might raise a counter argument as to the analysis
above with his point being the House of Lords had to advocate a special rule in Fairchild due
to the facts of the case being on the inability of medical science not being able to determine
the specific cause of an individual’smesothelioma. Therefore, complications arose as regards
to the courts efforts in compensating those victims who have sought redress for their
suffering. Hence, not only can one argue the Fairchild principle applies to only medical
5
Bastian A. Zahn, Harmful conduct as the touchstone of causation: an analytical comparison of Barker v Corus and Julian
Edin. L.R. 2011, 15(2), 197-218, 218.
6
[Lord Bingham 58-66] Lord Roger [113-118]
7
D Cooper, Mesothelioma, asbestos and causation J.P.I. Law 2003, Mar, 1-14 (10)

3. negligence cases, it would be very difficult to see such reasoning being applied in the context
of a particular case of which it is possible to establish the particular cause of injury or risk.
Therefore, in an attempt to answer the question at hand, the Fairchild principle did not depart
from the normal rules as regards to the casual questions which are asked for the purposes of
attribution of responsibility. Even though the traditional but for test could not be satisfied
here as firstly the disease is not aggravated by further exposure to asbestos of by which the
risk increases in proportion to quantity of asbestos fibres which one may inhale be it one or
many fibres. 8
However, comparing and contrasting the arguments for and against why the orthodox rule on
causation may have been departed, It sounds like Gary Meggitt argument sounds like the
weakest argument as the court were driven more on policy considerations as discussed earlier
in determining as regards to how causation would be interpreted to mean. Therefore
inrelation to Fairchild, If the claimants could demonstrate that one employer had materially
increased the risk of contracting mesothelioma they were entitled to claim full compensation
from that one employer as Gideon cohen words, damage would mean in this context not only
as an attack on the legal person of the victim, but as an attack on his ability to claim in the
future for physical harm which has been or is going to be inflicted.9
This line of evaluative thought is also seen in Barker v Corus Uk Ltd 10
of which here the
defendant had contracted mesothelioma from exposure to asbestos having worked for the
defendants between 1960-1968. But however since he became self-employed after this
period, the defendant sought to rely on the argument that the principle established in Fairchild
ought not to apply, as his exposure to asbestos whilst being self-employed being the reason
for such. However, it was held Fairchild did apply as Mr Barker was able to demonstrate the
8
G Meggitt, The "rock of uncertainty" - mesothelioma, insurers and the courts J.B.L. 2013, 6, 563-584,577.
9
G Cohen, Fairchild, Gregg v Scott, and damage to what? C.S.L.R. 2009, 5(1), 109-123 (110)
10
[2006] 2 AC 572

4. defendant breach of duty materially increased the risk of contracting the disease. Therefore,
not only did the House of Lords offer a novel interpretation of what Fairchild had decided,
Jane Stapleton for instance advocates Barker v Corus analysis is not limited to asbestos
induced mesothelioma cases, but other medical conditions.11
But however, critics once again might raise a counterargument that it seems Fairchild and
Barker was policy driven cases themselves, as even John stapleton himself acknowledges the
resolution in the problems in this type of cases was more tied upon policy judgments about
when the claimants ought to succeed and for what damage, than simple assessment on how to
draw upon scientific understanding, therefore the application of Barker in Fairchild might
have caused an unprecedented problem as regards to the judicial interpretation of policy
judgments which might differ from case to case and focus on the facts of each individual case
instead of a certified general principle.12
Therefore, in an attempt to answer the essay question at hand, it could be argued the decisions
in Fairchild and Barker have extended the nature of the orthodox meaning of cause in regards
as to which casual questions are asked for the purposes of attribution of responsibility. Hence,
in literal terms, but for causation will not always provide the tools that we need, proving
causation beyond the but for test in an attempt to reach a conclusion that is fair to both the
claimants and defendants would provide the tools we need.
11
J Stapleton, Unnecessary causes L.Q.R. 2013, 129(Jan), 39-65 (58)
12
Ibid, [65]

5. Another argument as regards to a shift away from the but for test to a loss of chance seems to
be what was decided in Gregg v Scott.13
Here, the court applied the strict balance of
probabilities test in Hotson and therefore held loss of chance was not recoverable in medical
negligence claims as the claimant was prospect of recovery was at 42 % before the delay.
Hence, the claimant failed to establish the defendant breach would have increases for instance
his prospect of recovery beyond the 50 % threshold. Therefore the majority in Gregg in the
context of the essay question at hand did express a form of judicial scepticism with regards to
claims of this kind of which did introduce a loss of chance recovery, which would disturb the
conceptual structure of tort law, and introduce uncertainty in the application of the law.
Therefore on the basis of the decision in Gregg, the traditional but for test was ignored, for a
loss of chance calculation with its aim to then compensate on a proportional basis.
However, critics might disagree with the argument as made above, with reference to Lord
Nicholls of Birkenhead dissent in Gregg of which he argued it is irrational and indefensible to
argue in both of these cases at hand were patients were worse off, and in both cases the
doctor was in breach of his duty to his patient, But it was said, in one case the patient has a
remedy, in the other he was not. Hence, Lord Nicholls of Birkenhead advocated the law
should recognise the existence and loss of power as well as those more favourable a result
that would be impossible if the all or nothing approach of the balance of probabilities were
applied. 14
13
[2005] 2 AC 176
14
[2005] 2 AC 176, 189

6. Furthermore, another argument which does seem to make a case for the modification of the
but for test is what was decided in Chester v Afshar 15
of which a more flexible approach to
the application of the but for test was adopted. Here, the defendant performed an operation on
the claimant with a very small risk of complication, of which he failed to warn the patient of
this risk. Nevertheless, there was no evidence to suggest she would have refused to go ahead
with the operation if she had been warned.
The House of Lords took a more flexible approach in the application of the but for test of
which the majority agreed the but for test had to be modified on the grounds of policy
reasons. Hence, in the words of Lord Hope, since the injury was intimately involved with the
duty to warn, which is the duty owed by the Mr Afshar who performed the surgery that Miss
Chester consented to, is to be regarded as the same product of the very risk that she could
have been warned about when she gave her consent. Therefore it would be held in the legal
sense there has occurred a breach of that duty. The reasoning here it could be argued was not
on the grounds of the normal rules of causation but on the ground for remoteness with the
argument being the chances of the operation going wrong were so slight if the claimant
postponed the procedure to a later date, it was more likely that not she would not have
suffered the disability of which she was claiming.
However, straightaway critics might argue the reasoning for a case of remoteness in Chester
sounds weak and is not of substantive content. As majority of the law lords (Lord Bingham
and Hoffman dissenting) based their conclusion on policy grounds of upholding patient
autonomy, hence which justified a narrow and modest departure from the traditional
causation principles. Further seen in Lord Steyn comment about advocating for the claimant
being entitled in to succeed as the result in this case is in accord with one of the most basic
15
[2004] UKHL 41

7. aspirations of the law, namely, to right wrongs of which therefore the decision reflects the
expectations of the public in contemporary society.16
On an evaluative note, it sounds like the arguments for the decision in Chester sounds like the
weaker argument as commentators such as John Stapleton argues conclusively the Chester
case by ignoring the orthodox and normative question of causation, has led to the judgement
in Chester appearing as judges being forced to come up with exceptional unorthodox rules of
causation, of which therefore,has produced confusion and obfuscation.17
Hence for this
reason, in an attempt to answer the question at hand, one could conclude as regards to the
causal questions which are to be asked for the purposes of attributing responsibility, the but
for test is would not always provide the tools that we need, going beyond the definition of
this test with a view of modifying it, can provide the tools which we need.
Penultimately, another argument which does suggest a move away from the orthodox
causation rules, to a focus more on the material contribution to the injury by emphasising
more on placing the burden of proof on the defendant rather than on the claimant is what was
decided in Mcghee v National Coal Board 18 of which Lord Wilberforce in this case,
appears to accept the possibility that in the absence of conclusive proof of a link between
fault and damages, liability may be imposed upon a defendant whose negligence increases the
risk of a particular loss occurring. Hence, a shift as regards to the burden of proof on to the
defendant of which the D is made liable for damages which by the normal application of the
but for test, it cannot be proved the D personally caused19
16
[2004] UKHL 41 at [24] and [25].
17
J Stapleton, Occam's razor reveals an orthodox basis for Chester v Afshar L.Q.R. 2006, 122(Jul), 426.
18
[1972] 3 All E.R.
19
J Stapleton, “The Gist of Negligence: Part II 1988 104 LQR 389, 404.

8. However, critics such as Martin A. Hogg disagree with the Lordship reasoning Mcghee that
there was no essential difference between the defenders having materially increased the risk
that the pursuer would contract dermatitis and having materially contributed to that
dermatitis. The reason being is he argues creating a risk of harm is not the same as causing
that harm as in a fictional sense; a defendant would be liable for damages which he in actual
sense he had not caused but only created the risk of its occurrence. 20
This notable problem as described above was later confirmed in Wilsher v Essex Area Health
Authority21 which the House of Lords reaffirmed the centrality of the but for test to issue of
causation in medical negligence cases. Hence, without conclusive evidence that the hospital
negligence had been the operative cause, liability could not be imposed. Therefore, on an
evaluative note, as established in Wilsher that the Mcghee did not reverse the burden of proof
which always remains on the claimant, the but for test had been re-established.
In conclusion, for the above reasons discussed above, one could advocate for the reasoning
that but for causation will not always provide the tools that we need, material contribution to
the risk, and loss of chance recovery, appear to be the most conclusive criteria as to what is
needed for the purposes of attributing responsibility.
*LLB Law Student University of Southampton.
20
Martin A. Hogg Re-establishing orthodoxy in the realm of causation Edin. L.R. 2007, 11(1), 8-30 (14)
21
[1988] AC 1074