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)
Continuity mistake: When Lister is fixing his robot goldfish, he picks it up with his right hand, then after the camera cuts, he puts it back into the tank with his left hand. (00:06:00)
Continuity mistake: When Lister rides his bike in the first scene, there is a Union Jack just behind his seat. When he stops, a US flag has appeared below it. (00:01:45)
Continuity mistake: The cuts on Lister's robot goldfish disappear when he throws it back into the tank after fixing it. (00:06:00)
Continuity mistake: When Lister cuts himself shaving he moves his locks behind his back, then in the next shot, they are over his shoulder again. (00:12:55)
Continuity mistake: When the cat priest dies, the hat he is wearing falls onto the bed above his head. When the shot changes the hat is gone. (00:26:35)
Continuity mistake: The food dispenser in the drive room is now in the place that the door to the Captain's office was in the previous episodes. (00:16:15)
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)
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)
Continuity mistake: When Rimmer is talking to Lister before the exam and says they are friends, Lister replies "When?" Lister has a can of beer on the bunk, with the label facing the camera. Two shots after, the label is suddenly facing away from the camera. A couple of shots after that, the label is suddenly facing the camera again. (00:23:15)
Continuity mistake: When Lister is revising for the exam, he opens a can of beer which sprays foam onto the table, and onto his cigarettes, when he opens it. A few seconds later, the sprayed foam disappears from the table. (00:19:30)
Continuity mistake: When the Cat is eating the food set out by Lister, there is a cloth on the table. When Lister is asking where the other kitties are, the cloth is shown near the centre of the table. Rimmer then says he wants it off the ship, and the cloth is suddenly further to the right of the table. (00:27:45)
Other mistake: Rimmer's badge of rank is missing from his short sleeved uniform. All other uniforms in the series have the badge. (00:15:10)
Visible crew/equipment: When both Rimmer and his future echo walk through the door from the captain's office, the edge of the set can be seen. (00:15:09 - 00:16:04)
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