Terrorform - S5-E3
Continuity mistake: When the crew finds the charm gravestone, Kryten looks at the Cat. Then in the next shot, Kryten looks at the Cat again. (00:14:25)
Continuity mistake: When the crew are backing away from Pete, the way they are standing changes between long shots and close ups. (00:26:10)
Emohawk - Polymorph II - S6-E4
Continuity mistake: At The End of the episode when Lister hands Duane the cannister, the shot changes and Lister is facing the opposite direction. (00:27:05)
Continuity mistake: When Kryten says 'you bet your ass' his cigarette has switched hands between shots. (00:12:00)
Continuity mistake: At The End of the episode, when the future Lister and the babies appear, Rimmer has his arms folded. In the next shot, Rimmer's hands are on his hips. Also, Lister's locks change positions. (00:27:50)
White Hole - S4-E4
Continuity mistake: When Kryten tells the toaster not to offer Lister any grilled bread products, Lister is looking down at the table behind him. In the next shot he is looking over his shoulder at the camera. (00:02:50)
Continuity mistake: After Rimmer walks out of Lister's exam at The End of the episode, you can see he walks into the sleeping quarters, yet in the next shot he is walking down a corridor. (00:28:30)
Continuity mistake: When remote controlled Lister is strangling the Cat, his locks are partially over his left shoulder and partially behind his back. When Lister picks up the bazookoid, his locks are all over his left shoulder. (00:23:10)
Continuity mistake: After the Cat starts to cry, he is looking at Kryten and Lister. In the next shot he is looking down. (00:04:50)
Continuity mistake: When the Cat asks if fish swim south for the winter, Kryten is looking at him. In the next shot, as Kryten answers, Kryten is looking up and away from the Cat. (00:02:05)
Continuity mistake: When Able screws Kryten's head on, he is standing in front of him. In the next shot, Able is behind Kryten next to the table. (00:15:30)
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