Mansfield v Weetabix Ltd [1998] 1 WLR 1263

Foreseeability of risk is about whether a reasonable person could predict that an action might cause harm. If a risk is foreseeable, there's a duty to prevent it. Courts often use this concept to determine if someone is negligent.

Causation connects a person's actions to an injury or damage.

• There are two types: cause-in-fact, which asks if the harm wouldn't have happened "but for" the action, and proximate cause, which looks at whether the harm was a foreseeable result of the action.

An accident caused by a driver's disability raises questions about liability.

• If the disability was sudden and unexpected, the driver might not be at fault.

• If it was known or could be foreseen, this could lead to negligence.

Determining if a driver is at fault involves examining their behavior and the events leading to the accident. Factors like reckless driving, ignoring traffic rules, or failing to address known risks can indicate fault.

Terence Mervyn Tarleton ("Lorry driver"), employed by Weetabix Ltd ("First Defendants"), was unaware that he suffered from a medical condition known as malignant insulinoma, which can induce hypoglycemia—a state where the brain lacks sufficient glucose to function properly.

During a 40-mile journey, the Lorry driver exhibited signs of erratic driving, including two separate incidents of unusual driving behavior and a minor accident with another vehicle.

• Later, the lorry driver failed to negotiate a bend, causing the lorry to crash into Shop premises at Bon Marche Stores, Upper Tean, Stoke-on-Trent, Staffordshire, and to its contents ("Plaintiffs' shop") resulting in significant damage to the building.

In the subsequent lawsuit filed by David Mansfield and Hazel Jean Mansfield ("Plaintiffs") seeking damages, the judge found that it was unlikely the driver completely lost consciousness before the crash.

• However, the judge determined that the driver's hypoglycemia impaired his ability to drive properly, suggesting that had he realized or appreciated this impairment, he would not have continued driving.

Despite these findings, Collins J. (“Judge”) concluded that the driver had not completely lost control of the lorry, thus ruling that the Defendants were negligent and liable for the damage caused to the Plaintiffs' shop.

The Defendants appealed against this decision, questioning the liability attributed to them and the determination of negligence based on the facts presented.

The Court allowed the appeal and reversed the original decision.

• The key question was whether a driver who caused an accident due to a disabling condition could avoid liability if the condition developed gradually and the driver was unaware of it.

• The Court held that the standard of care for a driver in this situation was that of a reasonably competent driver who did not know they had a condition impairing their ability to drive.

• Applying a strict liability standard without considering the driver's lack of awareness would have been incorrect.

In this case, the lorry driver, employed by the first Defendants, did not know about his malignant insulinoma, which led to hypoglycaemia and caused the accident.

• The Court found that he could not have reasonably known about the condition's impact on his driving.

• Therefore, the Court determined that he was not negligent, and the first Defendants were not liable for the damage caused by the accident.

• The Court also clarified that criminal law required a different test, focusing on whether the Defendant was driving at the time. This did not apply to civil cases, where negligence was the issue.

In light of these findings, the Court dismissed the claim against the first Defendants, overturning the lower court's decision.

This case illustrates several key legal principles surrounding negligence and liability.

The facts reveal how a driver's unawareness of a disabling medical condition, combined with the gradual onset of symptoms, led to an accident.

The judgment emphasizes the importance of considering a Defendant's knowledge and awareness when assessing negligence.

• It highlights the distinction between civil and criminal law standards, particularly regarding the requirement of automatism in criminal cases versus the negligence standard in civil cases.

Ultimately, the court's decision underscores the significance of foreseeability, causation, and the reasonable standard of care in determining liability.

Defendant didn’t realise he had hypoglycaemia and didn’t realise that his ability had been severely impaired.

He crashed into Plaintiff’s shop who sued him for negligence.

HL said that the standard of the duty of care was that of a “reasonably competent driver unaware that he was or might be suffering from a condition that impaired his ability to drive.”

• If no “awareness” was considered it would be a strict liability test.

• In this case he could not reasonably have been aware of his condition.