In a rare moment of escape from the oppressive boarding school in Lindsay Anderson’s If…., Mick Travis (Malcolm McDowell) and Johnny (David Wood) pay a visit to the local town. In the street, they begin a pretend knife fight.
The scene was filmed from across the road, and the reactions of the passers-by are genuine. One reaction, however, was a little on the extreme side. A passing lorry driver saw the boys, and—despite the fact that they were miming, without actual knives in their hands—he thought the fight was real.
Inspired by a rather peculiar sort of civic responsibility, the man stopped his lorry, ran over to Malcolm McDowell (who appeared to be winning), and hit him on the back of the head with a hammer.
History doesn’t recall whether McDowell required medical attention, or what became of Cheltenham’s have-a-go hero, but at least they got the scene done. (Although not before accidentally capturing a reflection of the camera crew in the windows of a passing bus – see below.)