Causation Issues
Causation
The courts take a common sense approach to causation. The matter should not be approached in the manner in which a scientist or philosopher might approach the issue.
Many incidents and accidents occur as a result of multiple causes attributable to several people. It does not follow that each such person may be deemed to have caused the accident from a legal perspective for the purpose of liability in negligence.
The question of whether the defendant’s acts or omissions have caused the claimant’s loss of damage, in the legal sense, is a matter of both fact and legal policy. Many incidents and events have multiple causes. The courts take a common sense approach.
The Civil Liability Act allows for apportionment of fault and contribution where the claimant and/or one or more defendants are at fault. This has reduced the need for courts to categorise one person or another as having caused the loss or damage.
Approach
In addition to the requirement for factual causation, the courts apply a material cause test. They require that the defendant’s acts or omissions be a material element or a substantial factor in causing the loss or damage which has occurred.
Ultimately, questions of causation may be determined by whether the loss or damage is more consistent with the defendant’s negligence than any other cause. This is a matter of factual inference.
Remoteness
Where loss or damage has been caused by the defendant, but it is too far removed from the negligence or other civil wrongs to be the subject of compensation, it is said to be too remote.
The rules on remoteness are matters of law which seek to provide limits on the extent of the loss for which compensation may be recovered. The rule of remoteness may limit the extent to which the claimant may recover or may recover entirely.
Intervening Act
Where some new act intervenes between the negligent act and the damage, it may be deemed to have been the cause or sole cause of the damage. In other cases, the “original” wrongdoer may have foreseen the intervening act. It is relevant whether he intended, was careless or reckless as to that act.
On one end of the spectrum, the intervening act may be inevitable and wholly predictable, in which event, it does not break the chain of causation. Where something happens in the normal course of things that can be expected, the original wrongdoer will usually remain liable.
Acts of Third Parties
The intervening act may be the predictable act of a third person, such as an attempt to rescue. The chain of causation is not broken.
Indeed, the defendant is likely to be liable also to the rescuer. The intervener’s action will commonly be intentional or reckless, involving a conscious risk.
The action of a third party may be a reflex or be inevitable, such as when the third party is put in a dilemma and takes emergency action accordingly by reason of something caused by the defendant’s negligence. This does not break the chain of legal causation, even though the action taken by the third party may have caused the loss in a literal sense.
If the third party’s action is completely unforeseeable and is the cause of the loss or damage, then the defendant will not generally be liable.
The defendant may be under a duty to take care to protect the claimant from the deliberate act, reckless or negligence of a third party. The duty may be to prevent the very thing that constitutes the deliberate act. For example, there may be a duty to take care to protect against burglary and theft, notwithstanding that the burglary and theft are intentional acts of a third party.
Intentional Act of Third Party
If those actions are intended, almost inevitable or likely, the defendant has deemed the cause. If the third party’s actions are foreseeable, although not necessarily probable, the court will look at carefully at the circumstances and judge whether they break the chain of legal causation.
The fact that a person acts deliberately or intentionally, causing injury to himself and/or another, does not necessarily break the chain of causation if the deliberate act is affected or rendered more dangerous by prior negligence on the part of the defendant. For example, where an employee is negligent due to the absence of instruction or the failure to provide a safe system of work on the part of his employer, the employee’s actions do not constitute a break in causation and responsibility in relation to the employer’s negligence.
Proving Causation
Causation may raise difficulties in evidence and proof. Expert evidence may be required to show a link between a particular act and its consequence. Expert evidence may be given in complex cases, from which the court may deduce issues of causation on the balance of probabilities. The question may be difficult and controversial in some cases, such as in Hanrahan v Merck Sharpe and Dohme, where the question arose as to whether the emissions from the defendant’s plant had caused damage to the claimant’s health and farm stock.
The res ipsa loquitur principle may assist the claimant in cases where causation is complex and denied. In effect, it creates a presumption of fault or negligence, where an event or occurrence is such that as would not normally occur without fault.
This, in effect, reverses the burden of proof. This may assist a claimant in actions such as those for product liability, where the manufacturer or other defendant is better able to give evidence on the causation.
More generally, negligence and causation may be inferred from facts which make it probable. Evidence may be called to support or contravene the inference.
Defendant’s Negligence
In some cases, the sole cause of loss or damage may be the defendant’s own negligence. The claimant may be contributorily negligent. See the sections on the Civil Liability Act, which provides for a reduction in damages where the claimant or defendants are partly at fault and have thereby contributed to the loss or damage.
The defendant’s negligence may be a material cause of the accident. It need not be the exclusive cause in order to establish the defendant’s liability.
This issue has arisen in a number of cases involving personal injuries, where there were difficulties in proving that exposure to a particularly harmful substance or circumstance while working for one of a number of employers in the same industry caused the injuries in question.
Exposure and Proof
Complex issues of causation and contribution may arise in exposure cases, where a number of defendant employers may have made a material contribution to the personal injury/condition. Under the Civil Liability Act, each may be fully liable subject to a right of contribution from other persons who are at fault.
The courts have been willing to hold each employer who is in breach of duty, liable in whole or in part, even if the claimant could not show that a particular employer, on the balance of probabilities, was responsible. This principle is applicable only where the impossibility of proving that the defendant caused the damage arises out of the existence of another potential causative agent which operated in a similar way.
Cumulative Causes
Where two parties have caused the loss, the courts endeavour to make an apportionment., without denying the claimant relief on the basis that he cannot establish precisely who caused the injury. The evidence called to enable the court to make a just apportionment should be proportionate to the level of loss and damage involved, and the uncertainties which are inherent in making a personal injury award of damages.
Many occupational injuries are the result of cumulative factors, which develop over time. Other occupational injuries appear at once.
Where damage is not cumulative but indivisible, apportionment is more difficult and may be impossible. Where there is an indivisible injury, the wrongdoer, who is the proximate cause, may be held liable in full for it.
Loss of Chance
In some professional negligence claims, recovery for the loss of chance may be allowed. In this context, the loss of chance refers to the possibility that had the relevant work or service not been negligent, there would have been a better chance / higher probability of an outcome favourable to the claimant.
In circumstances where it could not be proved, on the balance of probabilities, that the outcome would be worse or better, the House of Lords confirmed the requirement for proof of legal causation in law. It reasserted that the claimant must prove on the balance of probabilities that the particular injury was caused by particular wrongdoing or breach of duty on the part of the defendant.
In professional negligence cases, which turn on what the claimant would have done, had there been no negligence and the correct advice had been given, causation requires the claimant to prove, on the balance of probabilities, that he would have acted differently. The amount of damages is determined by the loss of the chance that the third party would have acted as alleged.
Defendant Causing Situation
Where the defendant’s negligence causes a situation in which a third person acts reasonably in a particular way, which contributes to the loss, this is unlikely to break causation and the defendant’s liability. It is a question for judgment in the circumstances as to whether the intervening action is reasonable.
The claimant’s loss may be the direct and natural consequence of the defendant’s fault or breach of duty, notwithstanding the intervention of human conduct whether by the claimant or a third party.
Mitigation
The issue of causation may be linked with mitigation. The claimant is obliged to mitigate his loss.
Where he acts reasonably in order to mitigate his loss, the chain of causation with respect to the defendant, will not be broken. On the other hand, where the claimant fails to mitigate, causation will be broken. Mitigation involves a duty to act reasonably.
Where there are separate and independent acts of fault by two or more parties, which would have caused similar damage, each is liable for the full amount suffered. Each has a causative effect.
Multiple Causes
A distinction is made between a supervening event which prevents an anticipated loss from occurring, and a supervening event which causes a greater loss, whether or not of the same kind. In the latter instance, the original loss is not reduced.
Where injuries are sustained in an accident caused by the defendant’s negligence in circumstances where it later emerges that the defendant was suffering from a debilitating unconnected illness, the defendant is liable to pay reduced damages because the supervening event has not been caused by the further wrongdoing.
Where a careless act of two defendants has prevented the claimant from discovering whose negligence caused damage, then on a public policy basis, both may be held liable. There must be evidence from which negligence can be inferred on the part of each. This may occur where there is a collision in the centre of the road or at a crossroads, injuring a passenger who is not at fault.
References and Sources
Irish Books
Tully Tort Law in Ireland 2014
McMahon & Binchy Law of Torts 4ed 2013
McMahon & Binchy Case Book on the Law of Torts 3ed 2005
Connolly Tort Nutshell 2ed 2009
Quill Torts in Ireland 4ed 2014
Fahey Irish Tort Legislation 2015
Healy Principles of Irish Torts 2006
EU and UK Texts
Lunney, M. and K. Oliphant Tort law: text and materials. 5ed 2013
Peel, Edwin, Goudcamp, James Winfield and Jolowicz on tort 19 ed 2014
Horsey, K. and E. Rackley Tort law. 6ed edition 2019
Deakin, S., A. Johnson and B. Markesinis Markesinis and Deakin’s tort law 7ed 2012
Giliker, P. Tort 5ed 2014
McBride, N.J. and R. Bagshaw Tort law 6ed 2018
Steele, J. Tort law: text, cases and materials 4ed 2017
O’Sullivan, J., J. Morgan, S. Tofaris, M. Matthews and D. Howarth Hepple and Matthews’ tort: cases and materials 7ed 2015
Horsey, H. and E. Rackley Kidner’s casebook on torts 13ed 2015
Clerk & Lindsell on Torts 22ed 2019
Charlesworth & Percy on Negligence 14ed 2019