Carlin was originally a Glaswegian, but was changed into a Cockney when Alan Clarke saw a then-unknown Ray Winstone walk in a unique way.
(at around 40 mins) Ray Winstone did not hit Phil Daniels with the sock containing the billiard balls despite the scene being done in one take. A crew member laid on the floor and handed Winstone another sock containing ping pong balls. Nevertheless, Daniels claimed he was very sore when Ray whacked him with the sock.
The picture was labeled one of the most controversial "video nasties" during the UK Video Nasties controversy of the early 1980s.
(at around 24 mins) The film has almost no music throughout except for the music played on Eckersley's radio during the scene when he frames Davis for 'stealing' it.
The earlier, original TV version of this movie, Scum (1991), made for the BBC but banned by them, was never screened until around 15 years later in 1991, after the director's death and part of a season on censorship. The BBC said that they banned it because "There was too much incident packed into too short a time and that they doubted the veracity." So they thought it was pure fiction, but they also said that it "looked too much like a documentary".