Hedley Byrne v Heller
The great case, known reverently to all students of the law as Hedley Byrne which established as long ago as 1954 the principle that one might be liable in tort for negligent misstatement, nothing more than confirming something that Lord Denning had dissentingly been grumbling about since 1951.
Some irony, therefore, that in that particular case, the defendant was found not to have had a duty of care, since he had effectively disclaimed one.