Quarantine - S5-E4
Continuity mistake: When Kryten injects the luck virus into Lister's neck, the gun disappears from Kryten's hand between shots. (00:23:25)
Quarantine - S5-E4
Visible crew/equipment: When Lister wipes down the biohazard cabinet, a boom mic can be seen in the top right of the screen. Also, just before the camera moves past the pillar, the entire microphone and arm can be glimpsed. (00:05:00)
Quarantine - S5-E4
Revealing mistake: As pointed out by Danny John Jules on the DVD Commentary, during the 'Feckles, Heckles, Hackles, Schmeckles' argument, Cat pushes his face right against Kryten's, leaving a brown makeup smear on Kryten's forehead. The mark is gone in the next shot. (00:19:45)
Quarantine - S5-E4
Visible crew/equipment: When the Cat tries to attack Rimmer in Quarantine, a boom mic can be seen at the top of the screen. (00:16:45)
Quarantine - S5-E4
Continuity mistake: After Lister gets the luck injection for the first time, he is holding his hat. In the next shot the hat is gone. (00:12:15)
Quarantine - S5-E4
Continuity mistake: When Rimmer is looking at the crew through the viewscreen in Quarantine, the reflection of the crew in the glass changes between shots. (00:21:20)
Quarantine - S5-E4
Audio problem: When Dr. Lanstrom says 'Life without pain has no meaning' Kryten begins to speak but no words are heard before the shot changes. (00:07:10)
Quarantine - S5-E4
Continuity mistake: When Lister gets the second luck virus injection, his locks move from in front of his shoulder to behind his back. (00:23:25)
Quarantine - S5-E4
Revealing mistake: When Lister uses the keypad to escape from Quarantine, more button lights turn off than he has actually pressed. (00:23:35)
Quarantine - S5-E4
Revealing mistake: When Lanstrom corners Lister, Kryten and the Cat, she is holding onto the fence. As she is a hologram, this would be impossible. (00:10:10)
Quarantine - S5-E4
Continuity mistake: Just before Dr. Lanstrom appears, Kryten is standing behind Lister. In the next shot, he has moved much further away from him, then moves back and forth between shots. (00:06:40)
Quarantine - S5-E4
Visible crew/equipment: When Rimmer asks the crew if they had forgotten Red Dwarf could only sustain one hologram, it shows a shot of the rest of the crew who say nothing. At the top of the screen, a boom mic can be seen. (00:03:00)
Quarantine - S5-E4
Audio problem: When Dr. Lanstrom says hello into the walkie talkie, her lips do not move. (00:08:40)
Quarantine - S5-E4
Audio problem: When Rimmer is talking to Lister, Cat and Kryten in the dress, the Cat says "We thought you'd gone nuts" and the shot cuts to Rimmer where the Cat then says "We were trying to heal you." When the shot is on Rimmer, the Cat's reflection can be seen in the mirror and his mouth doesn't move with the line. (00:21:05)
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