3. Comparing Approaches to Causal Problems

No abstract theory can provide a panacea for the problems of attributing cause to effect.⁷³ In certain situations the courts have to move away from the orthodox conceptual framework of the causal analysis in order to unravel particular difficulties of causation. Two types of thorny causal problem will be examined in more detail. The first is the occurrence of multiple causes of the injured party's harm. The second is more specific to the scenario of state liability and concerns the determination of causal responsibility for unlawful administrative decisions. Not only do these two factual situations illustrate how the two jurisdictions have tackled common causal problems, but they also serve to show how the French administrative courts have moulded the causal enquiry into an effective control mechanism.

3.1. Multiple Causes

Sometimes the injured victim's harm can be traced to one causal factor. (p.174) This is the exception rather than the rule. It is far more common for a variety of causes to be at the root of the injury. Limits on time and space preclude an exhaustive presentation of the English and French law approaches to this problem.⁷⁴ Instead, elements of comparative interest will be highlighted. In this analysis, it is helpful to adopt the analytical framework adopted by French lawyers to evaluate this problem,⁷⁵ looking in turn at the effects on causal responsibility of the activities of third parties, the contributory fault of the victim, and acts of nature.

3.1.1. Act of a Third Party

Liability of a public body may be either excluded or reduced if a third party's act had a causal contribution to the infliction of loss. First, liability may be excluded when a third party's act breaks the causal link between the administrative act and the resultant loss. In English law, there is no definitive test in the tort of negligence for determining whether the act of a third party constitutes a novus actus interveniens.⁷⁶ The foreseeability of the third party's intervening actions plays a significant role.⁷⁷ The degree of fault or culpability of the third party can also play a part, so that deliberate wrongdoing is more likely to break the chain of causation, but this is not always so.⁷⁸ The relationship between the defendant and the third party may also be important, such as the link between the borstal officers and borstal boys in the Dorset Yacht case.⁷⁹ The link between the claimant and defendant may likewise be important.⁸⁰ The effects of causal problems have been felt beyond the context of the causal enquiry stricto sensu. This is particularly so in relation to the duty of care in negligence. Courts have been especially wary of imposing a duty of care upon public authorities which are undertaking a regulatory or supervisory role over a third party.⁸¹ In certain circumstances, (p.175) acts of third parties may also insulate defendants from claims in the torts of nuisance⁸² and Rylands v Fletcher.⁸³

In French administrative law, whether the courts will find that the causal link is broken by the act of a third party similarly depends upon a number of factors.⁸⁴ A close relationship between the administration and the third party may mean that the latter's intervention does not exculpate the former.⁸⁵ The state of mind of the third party may also play a role, so that an involuntary act does not break causation.⁸⁶ In liability without fault for harm caused by a prisoner who has escaped from prison,⁸⁷ the length of time between escape and the act inflicting harm may be relevant.⁸⁸

Secondly, and significantly in the case of French administrative law, liability may be reduced by showing that the act of a third party causally contributed to the claimant's loss. The rules in French administrative law are particularly harsh on claimants. If it is shown that a third party did contribute to the occurrence of the claimant's injury,⁸⁹ the administration will be liable to pay solely the portion of the damages for which it is responsible.⁹⁰ Unlike in English law, an obligation of joint and several liability does not arise for multiple wrongdoers. Many of these cases of reduced liability are where the administration has been at fault in its supervisory or regulatory role concerning third parties.⁹¹ A particularly good example of this phenomenon is the recent case of Kechichian concerning the alleged negligence of the French banking supervisor, the Commission Bancaire.⁹² Depositors brought an action against the state alleging that the Commission Bancaire had failed properly to supervise a bank, the United Banking Corporation, thereby contributing to its failure (p.176) and the consequent loss of their deposits. The Conseil d'Etat found that the Commission Bancaire had indeed committed acts constituting faute lourde in the supervision of the bank. However, the Conseil d'Etat did not find the state liable for the whole amount of the loss. The primary causal contributor to the bank's failure was not the negligent supervision of the institution, but rather the fraudulent activities of its directors. Applying the rule of several liability, the Conseil d'Etat found the state solely liable for a portion of the total loss. Given the circumstances of the case, this was held to represent ten per cent of the lost deposits.

There are some exceptions to this rejection of joint and several liability. If more than one public body contributes to the claimant's harm, they will be held jointly and severally liable.⁹³ Furthermore, in the case of responsabilité sans faute, the courts have held that the administration is indeed jointly and severally liable for loss caused by a combination of its acts and those of any third party.⁹⁴

However, liability in French administrative law is generally not joint and several: the overall liability for the damage that has been caused to the victim is divided between the wrongdoers. This solution in French administrative law does accord with the prevailing causal theory of adequacy,⁹⁵ so that each contributor to the harm is liable for the causal potency of his act.⁹⁶ But it is nonetheless an extremely unfavourable rule for the victim.⁹⁷ Where there are a number of tortfeasors, the claimant will incur the cost and delay of having to bring several actions to recover the full extent of loss.⁹⁸ Should a third party prove insolvent, the victim will have to shoulder a portion of the loss. One commentator has argued that the rule stems from the belief that the state ought not to act as guarantor for a third party's delictual debt,⁹⁹ particularly where the state has played a minor causal role in the infliction of the victim's loss.¹⁰⁰