Emohawk - Polymorph II - S6-E4
Continuity mistake: When Lister gives the Gelf the cigar, he looks over his shoulder at Kryten. In the next shot, he looks over his shoulder again. (00:11:50)

Continuity mistake: When the crew almost kill themselves, Kryten is holding the harpoon gun to his head. The point of the spear is missing but in the next shot it has reappeared. (00:23:30)
Terrorform - S5-E3
Revealing mistake: At the start of the episode, Kryten's real wrist can be seen just before he removes his hand. (00:02:30)

Revealing mistake: When the Dalai Lama explodes, there is a single shot where he has disappeared and a yellow cloth has taken his place just before the explosion. The cloth then lands in the background. (00:22:55)
Timeslides - S3-E5
Character mistake: The assassination attempt on Hitler in 1944 was in Rastenburg, not Nuremberg as stated in this episode. (00:08:50)

Timeslides - S3-E5
Revealing mistake: When Lister is hit in the face with the snowball, some of the snow lands on Rimmer's hologramatic uniform. (00:07:40)

Stasis Leak - S2-E4
Revealing mistake: Rimmer, Lister and the Cat are not visible in the mirror when the crew member finds them in the shower. (00:10:25)
Continuity mistake: In the disco when Lister complains about the female Lister's attempts to impress him, his hair is in front of his left shoulder, then behind it. (00:19:10)
Visible crew/equipment: When the Cat licks Better Than Life's host, there is a shadow of a boom mic at the top of the screen on the wall. (00:19:35)
Continuity mistake: When Lister sees the future echo in the drive room, Rimmer points when he says 'Shut up.' However when the scene plays out again, Rimmer's arms stay down by his sides. (00:15:00 - 00:16:00)

Continuity mistake: Just after Kryten says 'you bet your ass' he is holding onto his groinal attachment over his shoulder. In the next shot, his arm is lowered. (00:12:00)
Continuity mistake: When the Cat picks up the golf clubs, his hair is sitting on his left shoulder. In the next shot it is behind his back. (00:10:40)
Suggested correction: His hair moved to his left shoulder when he turned his head and picked up the clubs, but you can see his hair go back behind him when he straightens his head.
Continuity mistake: After the Cat incapacitates Lister, the Cat complains about his collar being untidy, then steps aside. The next shot shows Lister stood on his own and the Cat is not visible at all. There was no time for the Cat to walk that fast between shots. (00:23:20)
Revealing mistake: When Rimmer is typing on the keyboard, what he is saying does not match what he is typing. He is typing randomly. (00:12:20)
Factual error: The polymorph goes through a metal pipe and a tap which bulges and becomes mis-shapen. The tap then changes back to its original shape, which is impossible. (00:18:00)
Suggested correction: It's impossible using today's technology, but maybe not in the future. Maybe they have metallic-like materials that flex back to a previous form after deformation.