Continuity mistake: When Lister sarcastically thanks the Cat for visiting him, Lister looks forwards, but in the next shot is looking at the Cat. (00:03:35)
Revealing mistake: One of the escort boots passes through a wall as it goes round a corner. (00:10:10)

Visible crew/equipment: When the crew are standing before the Judgement computer (when Lister is worrying that he will be sent to prison) if you look above Lister's head you can see a microphone bob up and down into shot. (00:11:10)
Factual error: The justice computer states that Rimmer is guilty of 1167 counts of 2nd degree murder, each carrying a sentence of 8 years giving a total of 9328 years. This is equivalent to 1166 counts. (00:14:00)
Revealing mistake: When the simulant pulls the knife out of his chest, you can see the knife is a dummy. As the handle is pulled back, the blade does not move at all. (00:25:30)
Answer: It's Queen Victoria, someone any Englishman would recognize, and needed no introduction.