Peter Mullan was horrified to learn that the film's production company, FilmFour, had accidentally burned over 30 minutes of footage. This was due to a clerical error.
In the pub scene (about 7 minutes in) you can spot Robert Urich in the crowd. He is not listed anywhere in the credits so may have just been there.
While in the van John(Stephen McCole) and Tanga (Frank Gallagher) listen to a Billy Connolly cassette. Michael(Douglas Henshall) played Billy Connolly's son in law in Down Among The Big Boys.
Gary Lewis and Stephen McCole both also appeared in Postmortem(1998) starring Charlie Sheen.
In 2022, the National Theatre of Scotland premiered a new stage musical adaptation of the film. The cast of the musical included Paul McCole, whose brother Stephen played the role of John in the original movie.