Continuity mistake: In several episodes of the show, Richard Beckinsale's hair changes length and style during individual episodes.
Suggested correction: Not a mistake. The show takes place over more than a year in the prison. People change their hairstyle and length during that time. Just because episodes are next to each other does not mean they happen within a very short period of time.
While the mistake is vague and should include a specific example or two, the mistake is saying that within an episode the hair changes, not that the hair changes between episodes.
Continuity mistake: At the end when Fletcher returns to his cell after a weekend at home his cell is on the ground floor. All other episodes it's the first floor.
Continuity mistake: Just after Warren says "we want a riot," the canteen door is already open and the prison guard is seen going through it. A few seconds later the guard is seen again banging on the door to get out.
Continuity mistake: In the episode 'Happy Release' we learn Blanco is in for a robbery. However, in this episode he is in for the alleged murder of his wife.