Introduction
Apportionment of liability between tortfeasors in negligence law addresses how damages are allocated when multiple parties are responsible for a single harm. Causation is a key component in establishing liability, requiring a direct link between the defendant's conduct and the claimant's loss. The principles governing this area involve legal tests such as the "but for" test, doctrines of material contribution, and considerations of remoteness of damage. Understanding these concepts is essential for analyzing how courts determine responsibility among multiple defendants in negligence cases.
Causation in Negligence: Basics of Liability
The "But For" Test
The "but for" test serves as the basis of factual causation in negligence. This criterion asks whether the harm would have occurred but for the defendant's conduct. In situations involving multiple parties potentially contributing to harm, the complexity of applying this test increases, necessitating careful examination of each actor's role.
In Barnett v Chelsea & Kensington Hospital Management Committee [1969], the court held that a doctor's negligence did not affect the patient's outcome, as the death resulted from arsenic poisoning unrelated to the doctor's actions. This case illustrates how the "but for" test can absolve a party if their negligence is not the direct cause of harm.
Remoteness of Damage
The doctrine of remoteness limits liability to damages that are a foreseeable consequence of the defendant's actions. Originating from Overseas Tankship (UK) Ltd v Morts Dock and Engineering Co Ltd (The Wagon Mound No 1) [1961], foreseeability is central to determining whether a defendant should be held liable. In this case, the court concluded that liability should not extend to damage that appeared too remote or unlikely from the vantage point of a reasonable person.
Dividing Liability Among Multiple Tortfeasors
Joint and Several Liability
When conduct by multiple defendants results in a single, indivisible injury, joint and several liability permits a claimant to recover full damages from any one of the responsible parties, regardless of their individual degree of fault. This rule, exemplified in Fitzgerald v Lane [1989], allows claimants to obtain complete compensation, even if some defendants are insolvent or untraceable.
Joint liability ensures that the burden of a claimant's loss does not rest unfairly on them due to the complexities of pursuing multiple defendants. It also encourages responsible parties to seek contribution from others who share liability, promoting fairness in the legal process.
Contribution Between Tortfeasors
The Civil Liability (Contribution) Act 1978 enables courts to apportion damages among joint tortfeasors, allowing for a fair distribution of liability based on each party's involvement in the harm. The allocation considers factors such as:
- The nature and extent of each party's involvement
- The degree of blameworthiness
- The impact of each action on the resulting damage
This statutory mechanism ensures that while claimants receive full compensation, the financial responsibility among defendants reflects their respective roles in causing the harm.
Material Contribution and Risk
Material Contribution to Damage
In cases where it is difficult to establish causation due to multiple potential factors, the doctrine of material contribution provides an alternative basis for liability. As established in Bonnington Castings Ltd v Wardlaw [1956], a defendant may be held liable if their actions materially contributed to the harm, even if they were not the sole cause.
This principle is particularly relevant in industrial disease cases, where claimants are exposed to harmful substances from multiple sources. If the defendant's breach of duty contributed to the accumulation of harmful exposure, they may be found liable for the resulting injury.
Material Increase in Risk
When scientific uncertainty makes it impossible to determine which of multiple potential causes led to the harm, courts may apply the principle of material increase in risk. In McGhee v National Coal Board [1973] and further developed in Fairchild v Glenhaven Funeral Services Ltd [2002], liability arises if the defendant's breach of duty significantly increased the risk of harm to the claimant.
This approach addresses the challenges in proving causation where medical or scientific evidence cannot provide definitive answers. By focusing on the increased risk, the court ensures that defendants cannot avoid liability merely due to evidential gaps beyond the claimant's control.
Advanced Theories in Causation
Novus Actus Interveniens
A novus actus interveniens, or new intervening act, can break the chain of causation between the defendant's negligence and the claimant's harm. For an intervening act to sever liability, it must be unforeseen, voluntary (in cases of human actions), and sufficiently significant to supersede the original negligence.
In McKew v Holland & Hannen & Cubitts (Scotland) Ltd [1969], the claimant's own unreasonable action in descending steep stairs without assistance, despite knowing his injured leg might give way, was deemed a novus actus interveniens, relieving the defendant of further liability.
Concurrent Causes
Concurrent causes occur when independent acts by multiple parties simultaneously contribute to the harm. The legal distinction between cumulative causes—where actions combine to produce one harm—and alternative causes—where each action alone could have caused the harm—is significant.
In Performance Cars Ltd v Abraham [1962], the court addressed a situation where two collisions caused similar damage to a vehicle. Liability was assigned based on whether the defendant's actions added to the existing harm, ensuring that defendants are not unfairly burdened for damage they did not cause.
Examples and Applications
Industrial Disease Cases
In situations where an employee develops a disease after exposure to hazardous substances from multiple employers, the doctrines of material contribution and material increase in risk are applied. Each employer may be held liable for their contribution to the risk of harm. The case of Fairchild v Glenhaven Funeral Services Ltd illustrates this application, where the claimant contracted mesothelioma after exposure to asbestos during employment with several employers.
Multi-Vehicle Collisions
In chain-reaction traffic accidents involving multiple drivers, courts examine the contribution of each driver's negligence to the overall harm. Joint and several liability may apply, allowing the injured parties to recover full damages from any of the negligent drivers. Factors such as foreseeability, breach of duty, and any intervening acts are considered to determine each party's liability.
Conclusion
Novus actus interveniens and concurrent causes present significant challenges in establishing causation within negligence law. The interplay between fundamental principles like the "but for" test, doctrines of material contribution, and concepts of joint and several liability demonstrates the complexity of apportioning liability among multiple tortfeasors. Cases such as Bonnington Castings Ltd v Wardlaw, McGhee v National Coal Board, and Fairchild v Glenhaven Funeral Services Ltd showcase the courts' approach in addressing scenarios where traditional causation tests are insufficient due to scientific uncertainty.
Accurate determination of liability requires meticulous analysis of each defendant's actions, the foreseeability of harm, and the potential for any intervening acts disrupting the causal chain. By applying these principles, courts strive to achieve equitable outcomes that reflect the individual responsibilities of involved parties while ensuring that claimants receive appropriate compensation for their losses.
