Carroll v Fearon & ors established that negligence by a tyre manufacturer, involving potentially lethal tyre defects, could be demonstrated by overwhelming evidence of a defective manufacturing process or another specific negligent act being responsible for the defect, and defines manufacturers' responsibilities in cases of products causing injury.

The case arose out of a road traffic accident in which a car's tyre burst. The car veered into the opposite lane, where it collided with the car in which the Carroll family was travelling. Mrs Carroll sustained a severe brain injury and facial damage, and all the family was injured.

At trial, there was copious evidence relating to the specification of the tyre, the manu- facturing process and previous complaints – Dunlop having previously lost contested applications for specific discovery.

It was accepted that the tyre had suffered catastrophic tread strip. It was alleged this was because of a defect in manufacture. Dunlop contended the tread strip was due to abuse of the tyre by running it under-inflated for significant distances, which the judge rejected. Dunlop accepted the tread strip, but alleged that the defect was caused by supply of externally generated parts and it produced no evidence it had adequate quality control.

The judge found the tread strip was caused by inadequate rubber penetration of the steel cords of the tyre, producing inadequate adhesion. He did not have to identify which act or omission during manufacture caused this. In the Court of Appeal, Dunlop suggested there might have been defects in the rubber or brass covering on the steel cords which might have been inadequate to produce proper bonding.

It accepted it had not adduced evidence previously but argued that this was the claimant's responsibility. It alleged that the failure must have arisen in a process over which Dunlop had no control.

The Court of Appeal rejected these suggestions and made these findings:

It affirmed Grant v Australian Knitting Mills (1936).

A manufacturer cannot be held liable in negligence for damage resulting from a defect which could not have been avoided or detected by reasonable precautions, where he can prove the problem was caused by a reputable supplier providing unsatisfactory materials which remained undetected by reasonable quality control procedures.

If a manufacturer fails to investigate third-party claims at the time a claim arises against him, and/or adduce evidence of a reasonable quality control process, he does so at his peril.