Continuity mistake: When we see Rimmer's Death video, the atomic blast pushes him into the Captain's office. However, in "The End," Holly indicates that the two piles of dust next to each other in the centre of the drive room are Captain Hollister and Rimmer. (00:10:00)
Continuity mistake: When Lister tips his socks onto the floor, he throws the bin behind him, near the bunkbeds. But when he picks them up again, the bin has moved over in front and to the right of him. (00:08:20)
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. (00:23:30)
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. (00:15:25)
Revealing mistake: When the two Rimmers are exercising, there are no stars visible out of their window. (00:11:20)
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. (00:06:10)
Revealing mistake: When Lister goes to Rimmer's room the second time, the door opens before Lister hits the switch.
Answer: The cello is a large four-stringed instrument, which, when it is played, stands vertically on the floor between the player's legs (assuming they are seated). If it is to grow as large as the other instuments mentioned will, it would require a rather unseemly lack of femininity to be able to encompass it with the legs.
Rooster of Doom