Revealing mistake: During filming of the this episode, Craig Charles was called away for the birth of his son, Jack, so production manager Mike Agnew stepped in. Although Lister is wearing a space suit at the time you can still tell which part is Mike thanks to a continuity error - Mike forgot to put on Lister's plaster cast. (00:15:15)
Revealing mistake: When the Outland Revenue guy breaks Rimmer's thumb with the mallet, the mallet does not touch his thumb, but instead his fingers. (00:28:35)
Stasis Leak - S2-E4
Revealing mistake: In the opening, Holly gives an additional message saying "On our journey, we have encountered many strange and bizarre things. Only last month, we can across a moon which was shaped exactly like Felicity Kendal's bottom. We flew around that one a couple of times." Before Holly says "We flew around that one a couple of times", he can be seen about to say the line, but visibly hesitates, presumably waiting for his cue. (00:01:35)
Revealing mistake: During the last scene of the episode, the Cat keeps brushing against Rimmer's hologramatic shirt. (00:27:10)
Revealing mistake: When Lister uploads his memories, the wide shot shows various videos of Rimmer in the background, but in the close up it shows a plain white screen. (00:17:55)
Revealing mistake: When Lister and the Cat drop the gravestone and break their feet, you can see that it does not land anywhere near Lister's left foot. (00:26:55)
Revealing mistake: Holly's night cap is in front of the edges of his monitor. It should fade into the white border of his screen. (00:05:25)
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