Emohawk - Polymorph II - S6-E4
Continuity mistake: The Cat's earrings disappear when the emohawk attacks him. (00:20:00)
Continuity mistake: When Ace drives the bike out of the shed, the piece of wood is between the front wheel and the handlebars. In the next shot, the piece of wood is resting on his arms. (00:03:25)
Revealing mistake: When Kryten's head explodes, you can tell the head is a dummy. (00:08:05)
Revealing mistake: When Ghandi explodes, there is a single shot where he had disappeared before the explosion goes off. (00:22:35)
Continuity mistake: When Rimmer's mother is talking to him while he is hung upside down, she is stood about a foot away from him in one shot, then in the next she is about three feet away. (00:01:45)
Visible crew/equipment: When the bazookoid blasts hit the Polymorph near The End, you can see the stand that's holding the Polymorph at the bottom of the screen. (00:24:45)
Stasis Leak - S2-E4
Revealing mistake: When Rimmer hides under the table, he is not visible beneath the table when Lister and Rimmer walk in. (00:18:40)
Continuity mistake: When Lister and the Cat first see Lisa Yates on the screen, their shoulders are together. In the next shot there is a wide gap between them. (00:18:30)
Stasis Leak - S2-E4
Revealing mistake: At The End of the episode when the future Lister closes the door on the Cat and Lister, you can see the partial editing out of Lister and the Cat as the door closes. As this happens, Lister and the Cat disappear before the door has passed them. (00:26:50)
Continuity mistake: When the gunman ties the cable to himself, he walks past a window, then in the next shot he is stood in the centre of the same window. (00:15:40)
Revealing mistake: After Starbug lands on the 'high' Red Dwarf, Rimmer is running out of power and starts to fade in and out. However, Cat, who must be standing too close to Rimmer also fades, the backdrop being partially visible through him. (00:08:05)
Continuity mistake: When Rimmer gives Hollister the directives to sign, he holds the clipboard in both hands. In the next shot his left hand is under the first page. (00:02:15)
Out Of Time - S6-E6
Visible crew/equipment: When the future crew decide to leave, there is a shot of Lister holding the bazookoid as they walk towards the door. A boom mic is visible above him. (00:24:40)
Out Of Time - S6-E6
Visible crew/equipment: At the start of the episode, just before the Cat says his fridge free diet line, a boom mic shadow can be seen on Kryten's head and shoulder. (00:02:50)
Out Of Time - S6-E6
Continuity mistake: When Lister and the Cat wake up from stasis, Lister walks over to the computer and his locks are over his right shoulder. In the next shot they have disappeared. (00:12:50)
Suggested correction: Lister can only see M-Corp products and M-Corp employees. Cat is not an employee of JMC or M-Corp, so he disappears. Lister is the only member of the crew who is employed by M-Corp at this point.
Suggested correction: Cat was a descendant of the cat Lister brought aboard Red Dwarf. Would it be possible that the new owners might have stricter security controls, and Lister was sent to Stasis for a different reason?
Andy Benham ★
Inventing Deux ex machina explanations for a plot hole doesn't make it any less of a plot hole. M-Corp erases all of the Jupiter Mining Corporation's equipment, personnel and infrastructure from Lister's life. In no way is Cat a part of that. He has no connection at all to the Jupiter Mining Corporation, and until he meets him in Episode 1 no connection to Lister, either.
If M-Corp only erased JMC equipment from Lister's life, then Kryten, who belongs to DivaDroid and not the JMC, wouldn't have disappeared either. He disappears as he doesn't belong to M-Corp, not because he belongs to the JMC. Cat has no connection to M-Corp, as he wasn't a part of the JMC (as you pointed out), and is therefore erased for Lister.