Labour Lawyer in South Africa
Wrongfulness Of Omissions
The test for factual causation is the sine qua non ( or “but for” ) test. It entails the hypothetical “thinking away” of a particular alleged cause of a result and asking whether, absent that cause, the offending result would nonetheless have occurred. If the answer is in the affirmative, the alleged cause did not in fact cause the result. In the case of wrongful omissions, the application of the sine qua non test typically requires the substitution of a hypothetical course of lawful conduct for the omission that actually occurred.
In Siman & Co (Pty) Ltd v Barclays National Bank Ltd 1984(2) SA 888 (A) Corbett JA said
the following in a minority judgment ( at 914 in fine ):
“The enquiry as to factual causation generally results in the application of the so-called “but-for” test, which is designed to determine  whether a postulated cause can be identified as a causa sine qua non of the loss in question. This test is applied by asking whether but for the wrongful act or omission of the defendant the event giving rise to the loss sustained by the plaintiff would have occurred. In a case such as the present one, which is uncomplicated by concurrent or supervening causes emanating from the wrongful conduct of other parties ( I shall deal in due course with the defence of contributory negligence ), the but-for or, causa sine qua non, test is, in my opinion, an appropriate one for determining factual causation.
In order to apply this test one must make a hypothetical enquiry as to what probably would have happened but for the unlawful act or omission of the defendant. In some instances this enquiry may be satisfactorily conducted merely by mentally eliminating the unlawful conduct of the defendant and asking whether, the remaining circumstances being the same, the event causing harm to plaintiff would have occurred or not. If it would, then the unlawful conduct of the defendant was not a cause in fact of this event; but if it would not have so occurred, then it may be taken that the defendant’s unlawful act was such a cause. This process of mental elimination may be applied with complete logic to a straightforward positive act which is wholly unlawful. So, to take a very simple example, where A has unlawfully shot and killed B, the test may be applied by simply asking whether in the event of A not having fired the unlawful shot (ie by a process of elimination) B would have died. In many instances, however, the enquiry requires the substitution of a hypothetical course of lawful conduct for the unlawful conduct of the defendant and the posing of the question as to whether in such case the event causing harm to the plaintiff would have occurred or not; a positive answer to this question establishing that the defendant’s unlawful conduct was not a factual cause and a negative one that it was a factual cause. This is so in particular where the unlawful conduct of the defendant takes the form of a negligent omission. In The Law of South Africa (ibid para 48) it is suggested that the elimination process must be applied in the case of a positive act and the substitution process in the case of an omission. This should not be regarded as an inflexible rule. It is not always easy to draw the line between a positive act and an omission, but in any event there are cases involving a positive act where the application of the but-for rule requires the hypothetical substitution of a lawful course of conduct (cf Prof A M Honoré in 11 International Encyclopaedia of Comparative Law c 7 at 74 – 6). A straightforward example of this would be where the driver of a vehicle is alleged to have negligently driven at an excessive speed and thereby caused a collision. In order to determine whether there was factually a causal connection between the driving of the vehicle at an excessive speed and the collision it would be necessary to ask the question whether the collision would have been avoided if the driver had been driving at a speed which was reasonable in the circumstances. In other words, in order to apply the but-for test one would have to substitute a hypothetical positive course of conduct for the actual positive course of conduct.”
The above approach was embraced in International Shipping Co (Pty) Ltd v Bentley 1990 (1)
SA 680 (A), where Corbett CJ, writing for the full Court, said the following at 700 E:
“As has previously been pointed out by this Court, in the law of delict causation involves two distinct enquiries. The first is a factual one and relates to the question as to whether the defendant’s wrongful act was a cause of the plaintiff’s loss. This has been referred to as ‘factual causation’. The enquiry as to factual causation is generally conducted by applying the so-called ‘but-for’ test, which is designed to determine whether a postulated cause can be identified as a causa sine qua non of the loss in question. In order to apply this test one must make a hypothetical enquiry as to what probably would have happened but for the wrongful conduct of the defendant. This enquiry may involve the mental elimination of the wrongful conduct and the substitution of a hypothetical course of lawful conduct and the posing of the question as to whether upon such an hypothesis plaintiff’s loss would have ensued or not. If it would in any event have ensued, then the wrongful conduct was not a cause of the plaintiff’s loss; aliter, if it would not so have ensued. If the wrongful act is shown in this way not to be a causa sine qua non of the loss suffered, then no legal liability can arise. On the other hand, demonstration that the wrongful act was a causa sine qua non of the loss does not necessarily result in legal liability. The second enquiry then arises, viz whether the wrongful act is linked sufficiently closely or directly to the loss for legal liability to ensue or whether, as it is said, the loss is too remote. This is basically a juridical problem in the solution of which considerations of policy may play a part. This is sometimes called ‘legal causation’. (See generally Minister of Police v Skosana 1977 (1) SA 31 (A) at 34E – 35A, 43E – 44B; Standard Bank of South Africa Ltd v Coetsee 1981 (1) SA 1131 (A) at 1138H – 1139C; S v Daniëls en ‘n Ander 1983 (3) SA 275 (A) at 331B – 332A; Siman & Co (Pty) Ltd v Barclays National Bank Ltd 1984 (2)  SA 888 (A) at 914F – 915H; S v Mokgethi en Andere, a recent and hitherto unreported judgment of this Court, at pp 18 – 24.)”
In Lee v Minister of Correctional Services 2013(2) SA 144 (CC) the question arose whether
it could be inferred as a matter of fact that a previously healthy man had contracted tuberculosis as a result of the authorities’ failure to provide appropriate prophylactic care when they incarcerated him for several years in an overpopulated gaol, where tuberculosis was rife. Applying the sine qua non test, the SCA declined to draw the inference. A majority of the Constitutional Court disagreed, with specific reference to the substitution exercise called for by the sine qua non test in the case of omissions. Having reiterated the remarks of Corbett JA in Siman’s case about the limits of the substitution exercise, and having found that a “common sense” approach to factual causation might sometimes be more apposite, the majority nonetheless approved the substitution exercise, although expressing the following qualification:
“ Even if one accepts that the substitution approach is better suited to factual causation, the preceding discussion shows that there is no requirement that a plaintiff must adduce further evidence to prove, on a balance of probabilities, what the lawful, non-negligent conduct of the defendant should have been. All that is required is ‘the substitution of a hypothetical course of lawful conduct and the posing of the question as to whether upon such an hypothesis the plaintiff’s loss would have ensued or not’. What is required is postulating hypothetical lawful, non-negligent conduct, not actual proof of that conduct. The law recognises science in requiring proof of factual causation of harm before liability for that harm is legally imposed on a defendant, but the method of proof in a courtroom is not the method of scientific proof. The law does not require proof equivalent to a control sample in scientific investigation.
 Postulating hypothetical lawful, non-negligent conduct on the part of a defendant is thus a mental exercise in order to evaluate whether probable factual causation has been shown on the evidence presented to court. It is not a matter of adducing evidence, as the Supreme Court of Appeal appears to have found.
I accept that the postulate must be grounded on the facts of the case, but that is not the same as saying that there is a burden on the plaintiff to adduce specific evidence in relation thereto.
 What was required, if the substitution exercise was indeed appropriate to determine factual causation, was to determine hypothetically what the responsible authorities ought to have done to prevent potential TB infection, and to ask whether that conduct had a better chance of preventing infection than the conditions which actually existed during Mr Lee’s incarceration. Substitution and elimination in applying the but-for test are no more than a mental evaluative tool to assess the evidence on record. In my view, this hypothetical exercise shows that probable causation has been proved.”
It is submitted that the implications of these dicta in the present matter are the following: The alleged wrongful omission attributed to the third defendant must be thought away, and a hypothetical course of affirmative, lawful conduct must be substituted therefor, in the circumstances that otherwise prevailed. It does not have to be established as a scientific fact that such affirmative, lawful conduct would definitely (or not ) have made a difference. It simply has to be established whether the probable outcome would have been different from that which actually occurred. If so, a causal link is established; but if not, there is none.
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Personal Injury , Medical Malpractice and Labour Law