Confidence and Paranoia - S1-E5
Visible crew/equipment: In the medi-bay, when Rimmer says, "How about an anal reading?" a yellow microphone appears above his head. (You can see this if you watch the dvd on your pc, as some tv's can cut off the edge of the picture). (00:11:00)
Confidence and Paranoia - S1-E5
Revealing mistake: In the captain's office, the words 'Medical bay' have been painted on the wall. This was near The End of the episode and can be seen over Rimmer's shoulder while they are talking in the drive room. The set was obviously doubled with the medical bay, as the captain's office is not used in this episode. (00:23:25)
Confidence and Paranoia - S1-E5
Visible crew/equipment: When the skutters try to move Lister in the Medi-bay, you can see the cable which pulls Lister's chair in the bottom right of the screen. (00:12:40)
Confidence and Paranoia - S1-E5
Continuity mistake: When Lister is in the Medi-bay, he has his duvet on his lap. The angle changes and he has the duvet over his shoulders. (00:12:30)
Confidence and Paranoia - S1-E5
Continuity mistake: When confidence explodes outside the ship, a helmet appears on the walkway which was not there earlier in the scene. (00:26:50)
Confidence and Paranoia - S1-E5
Continuity mistake: When Confidence is telling Lister that his song was the greatest love song ever, Lister has his right hand on his lap, but in the next shot, his right hand is suddenly on the guitar strings. (00:19:35)
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