Continuity mistake: When Lister and the Cat are talking to the original Rimmer in the cinema, the new Rimmer enters and argues with the original. The original Rimmer makes hand puppets, while the new Rimmer sits at the front. When Lister does the ippy-dippy, the Rimmers have swapped places. The new Rimmer says that he was there first, without complaint from the original.
Other mistake: When Lister reads Rimmer's diary, he reads the first entry, then his aunt's birthday in July and then the entry for Gazpacho Soup Day in November. Each time he looks for the next entry he flicks though the pages, yet every time he reads, it is from the start of the diary.
Revealing mistake: When Lister goes into Rimmer's new room, there is a slight glitch with the split screen. When Lister is laughing at Rimmer's newspaper headlines on the door, the camera changes and the first frame only has Lister and Rimmer with the scutters. In the next frame the second Rimmer appears and the scutter on the right has moved.