Knightley v Johns & Ors is a landmark case in the law of tort, particularly concerning the concepts of novus actus interveniens and causation. Decided by the Court of Appeal in 1982, the case explores the circumstances under which an intervening act breaks the chain of causation, thereby negating the liability of an original wrongdoer. The judgement in Knightley v Johns & Ors provides clarity on the application of foreseeability in establishing causation and liability in negligence claims.
Facts of Knightley v Johns & Ors
The facts of Knightley v Johns & Ors are central to understanding the legal principles established in the case. The defendant, Mr Johns, was driving negligently, which resulted in his car overturning near the exit of a tunnel. This accident prompted the attendance of two police officers who arrived at the scene on motorcycles.
A senior police officer was responsible for securing the accident scene but failed to properly seal off the tunnel entrance to prevent further traffic from entering. Upon realising this oversight, the senior officer instructed both police officers to ride their motorcycles through the tunnel on the wrong side of the road to close the tunnel entrance. This route was shorter but required travelling against the normal flow of one-way traffic, including a dangerous blind bend.
One of the officers, Mr Knightley, took the route as instructed but was involved in a head-on collision with an oncoming vehicle driven by Mr Cotton. Mr Knightley sustained serious injuries as a result of this collision. He brought legal action against multiple parties including Mr Cotton, Mr Johns (the negligent driver), the senior police officer who gave the instruction, and the Chief Constable of West Midlands.
Issues
The principal issue before the Court of Appeal in Knightley v Johns & Ors was whether Mr Johns remained liable for the injuries sustained by Mr Knightley, or whether the actions of the senior police officer and other parties constituted a novus actus interveniens—a new intervening act that broke the chain of causation from Mr Johns’ original negligence.
In addition to causation, the court also considered the question of whether Mr Knightley’s decision to follow the senior officer’s instruction and ride through the tunnel on the wrong side of the road was itself negligent and thus contributory to his injury.
Legal Principles
The judgement in Knightley v Johns & Ors is significant for its application of two important tort principles: novus actus interveniens and the test of foreseeability in causation.
Novus Actus Interveniens
The doctrine of novus actus interveniens holds that if an independent intervening act occurs after the defendant’s negligence and this act is sufficiently serious and unforeseeable, it breaks the chain of causation, relieving the original wrongdoer of liability for subsequent harm.
In Knightley v Johns & Ors, the Court examined whether the negligent instruction by the senior officer and his failure to close the tunnel entrance were such intervening acts.
Foreseeability and Causation
A key test for causation in negligence cases is whether the damage or injury was a reasonably foreseeable consequence of the defendant’s actions. The court in Knightley v Johns & Ors reaffirmed that liability attaches only where the damage is a natural and probable consequence of the defendant’s conduct.
Where the intervening act is not reasonably foreseeable, it may break the causal chain.
Reasonableness of the Claimant’s Actions
The court also reviewed whether Mr Knightley acted reasonably in following the senior officer’s instruction. If his actions were negligent, they could potentially contribute to or cause the injury, affecting the liability of other parties.
Knightley v Johns & Ors Judgement
In its judgement, the Court of Appeal held that Mr Johns’ negligent driving caused the initial accident but was not liable for the injuries sustained by Mr Knightley in the subsequent collision.
The court ruled that the senior officer’s failure to close the tunnel entrance and his instruction to ride through the tunnel against the flow of traffic were both negligent acts. More importantly, these negligent acts were held to be novus actus interveniens—new intervening acts that broke the chain of causation originating from Mr Johns’ negligence.
The reasoning was that while it was foreseeable that police officers would attend the crash scene, it was not foreseeable that the senior officer would give a negligent order for officers to ride on the wrong side of a one-way tunnel with a blind bend. This act was therefore a sufficiently independent and unforeseeable cause of the injury.
Furthermore, the court found that Mr Knightley’s decision to follow the senior officer’s instruction was not negligent. It was reasonable for him to comply with the order given by a superior officer in the line of duty.
Consequently, Mr Knightley was entitled to full damages from the senior officer, who was directly responsible for the negligent instruction and failure to close the tunnel. Liability for the injuries did not extend to Mr Johns.
Conclusion
In conclusion, Knightley v Johns & Ors [1982] 1 WLR 349 stands as a leading authority on the doctrine of novus actus interveniens and the principles of causation in English tort law. The Court of Appeal’s ruling clearly demarcates the boundary of liability for negligent acts and subsequent intervening causes.
