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Terrorform - S5-E3
Continuity mistake: When we first see Kryten, there is no long grass anywhere near him. When Lister rescues him, it has appeared from nowhere. (00:01:35 - 00:06:10)
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Terrorform - S5-E3
Continuity mistake: The cutting torch Kryten uses to cut his hand off appears from nowhere. (00:02:20)
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Terrorform - S5-E3
Continuity mistake: When Kryten cuts off his hand, all of the fingers on the hand are straight and level with each other, but when he goes to attach his eye to one of the fingers, the middle finger is suddenly raised. (00:02:35)
Terrorform - S5-E3
Continuity mistake: When Lister and the Cat type into the computer, the words are out of synch with the key tapping. (00:05:15)
Terrorform - S5-E3
Continuity mistake: At the start of the episode Kryten has crashed Starbug 1 onto the psi-moon. Lister and the Cat rescue him in Starbug 2, yet when the crew search for Rimmer in the swamp, they are in Starbug 1. (00:06:10 - 00:19:45)
Terrorform - S5-E3
Continuity mistake: Just after one of the hooded legions reads from the scroll, he manages to turn around and face the opposite direction in one camera cut. (00:10:45)
Terrorform - S5-E3
Continuity mistake: When Rimmer gets his robe torn off, he is looking forwards. In the next shot he is looking down. (00:11:00)
Terrorform - S5-E3
Continuity mistake: When the crew finds the charm gravestone, Kryten looks at the Cat. Then in the next shot, Kryten looks at the Cat again. (00:14:25)
Terrorform - S5-E3
Continuity mistake: After the crew fire at the Self-loathing Beast and the room fills with dust, the Cat's left hand is up in the air. In the next shot he is holding the bazooka with both hands. (00:17:00)
Terrorform - S5-E3
Continuity mistake: When Lister, the Cat and Kryten figure out how to escape, Kryten says 'precisely' and raises his right hand. In the next shot, both of his hands are raised. (00:22:15)
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