Continuity mistake: When Rimmer is standing on the beach and conjures up the green car you can see the wheels are partly in the sand. When he then gets into the car, tyre tracks are visible behind it. When he starts driving off, the tyre marks are now gone. (00:18:25)
Continuity mistake: When the Cat and Lister are playing golf, they stop next to a bed with Marilyn Monroe sitting on it. When the camera angle changes, they begin walking from the other side of the bed. Also Marilyn Monroe is now kneeling. (00:24:20)
Continuity mistake: As the crew enter the game, Lister pushes the door to the beach open. However in the next shot, the door is opening from the other side, i.e. Lister is pulling the door. (00:16:10)
Continuity mistake: When Lister puts his Better Than Life helmet on, the cable is hanging over his right shoulder. In the next shot it is hanging down over his left shoulder. (00:15:45)
Continuity mistake: When the bike appears on the beach, the front tyre is above the level of sand. In the next shot it has sunk by about an inch. (00:17:50)
Continuity mistake: The sand that lands on Rimmer's shoulder when Lister and the Cat drive away on the bike disappears in the next shot. (00:18:10)
Continuity mistake: When the Cat is kissing the photo of the mermaid, in the next shot the photo has disappeared. (00:24:50)
Continuity mistake: When Lister and the Cat put their sunglasses on, Rimmer's tie changes between camera cuts from over his shoulder to neat and straight. (00:18:00)
Continuity mistake: When Marilyn Monroe waves to the Cat on the beach, in the next shot her arms are by her side. (00:16:50)
Continuity mistake: When Lister is questioning how they can remake Casablanca, he is holding the video tape, but in the next shot, the tape has disappeared from his hand and is touching the control panel. (00:04:40)
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