The Donoghue v. Stevenson trial, also known as 'The Paisley Snail MiniTrial,' was responsible for establishing the tort law of negligence, which underpins manufacturers' legally obligated duty of care for their customers. The trial took place in Scotland and concluded with Lord Atkin's judgment in 1932.
The complaint brought to trial was from Ms May Donaghue, who had opened and consumed most of the contents of a bottle of ginger beer before discovering that a dead snail had been inside. She was later diagnosed with gastroenteritis. The defendant was the manufacturer of the ginger beer, Stevenson.
Although Donaghue could not sue on the grounds that she did not purchase the drink herself and therefore had entered into no contract with its manufacturer, her lawyers pursued a claim of injury through negligence. The defense successfully got the case dismissed on the basis of a lack of legal precedent for Donaghue's claim.
Later, a successful appeal to the House of Lords led to the establishment of a number of key legal principles. Chief among these were that, firstly, negligence is a tort and Stevenson was in breach of his responsibility for the safety of his product. Secondly, that all manufacturers have a duty of care to their customers.
In his judgment, Lord Atkin also established the 'neighbor principle,' which dictates that people must be held accountable for any of their actions and omissions which may cause injury to their 'neighbor.' Here, a neighbor was defined as anyone who would be so directly affected by a person's act or omission that that person should have considered them when planning the act or omission.