Continuity mistake: At The End of "Nanarchy", Kochanski's hair is brown. However, throughout series 8, her hair is blonde. And with everything going on in "Nanarchy" there would have been nowhere near enough time for her to dye it.
Continuity mistake: When Lister is lying on the top bunk talking to Rimmer about the 83 year old dad, he says "he'd probably pretend to be dead" as he puts is left hand on the side of his face. The camera cuts to Rimmer then back to Lister again, as he puts his left hand on the side of his face again. (00:01:55)
Continuity mistake: At The End of "Nanarchy" Starbug 1 flew underneath Starbug 2 at The End of the episode, yet in this episode when the scene is repeated, the ship flies around Starbug 1 instead. (00:05:50)
Continuity mistake: When Starbug crashes through a vent, Lister leans to his far right. In the next shot, he is leaning to his left. (00:09:20)
Continuity mistake: When Lister goes to hug Selby and Chen, his locks are over his right shoulder. In the next shot they are behind his back. (00:10:40)
Continuity mistake: When Thornton places the bracelet on Lister's arm, Lister's arm is at a straight angle, but in the next shot, his arm is at a rotated angle. (00:12:15)
Continuity mistake: The view of space outside the window in Rimmer and Lister's bunk shows a completely still background, but every other view of space through a window shows the ship moving. (00:14:10)
Continuity mistake: When Kryten's head falls off it bounces with no velocity, yet in the next shot it is quickly rolling out of the door. (00:06:55)
Continuity mistake: When Kryten tells Kochanski he doesn't have a penis, he turns away from her. In the next shot you can still see Kryten on the right of the screen as he turns away from her again. (00:07:20)
Continuity mistake: When Rimmer shows Lister the luck virus and sexual magnetism virus, there is less than half of the liquid shown in the test tube for the sexual magnetism, but when Rimmer is about to go to Hollister's dinner later on, there is more liquid in the test tube. There was also only one test tube of sexual magnetism for Rimmer to use. (00:12:15 - 00:18:10)
Continuity mistake: In the bathroom when Kryten says he does not want his corrupted files repaired, he holds out his arms. In the next shot when the guards stun him, they are by his side. (00:15:00)
Continuity mistake: Just after Kochanski jumps on Lister, she stands up and says 'I don't know what got into me' with her hand on her head. In the next shot, her hand is by her side. (00:16:35)
Continuity mistake: When Kryten is restored to his factory settings, the woman is pressing buttons on the keypad. In the next shot, her arm is by her side. (00:17:40)
Continuity mistake: When Rimmer walks down the corridor, his hair is a mess. When he enters the medi-bay it is tidy. (00:25:25)
Continuity mistake: At The End of the episode when Lister, Kryten, the Cat and Kochanski are dressed as the Dibleys, they walk into the corridor in a line and Kochanski stops when she bumps into the Cat. In the next shot there is a suddenly a space between them. (00:26:40)
Continuity mistake: When The Cat does his dance with Blue Midget, he stands behind one of the legs of Blue Midget and changes his clothes. The old clothes he throws on the ground when changing disappear in the wide shot of the landing area. (00:08:55)
Continuity mistake: When the Cat does his tap dance, he starts 20 feet away from Blue Midget and does not move from his position during the dance. When he finishes, he taps Blue Midget's leg. (00:09:30)
Continuity mistake: During the Cat's dance, he taps his feet and tilts his head back, which Blue Midget copies. In the next shot Blue Midget is looking downwards and then proceeds to do the same dance it just did in the previous shot. (00:10:00)
Continuity mistake: During the Cat's dance scene with Blue Midget, we see one shot of Blue Midget doing the air guitar move, but in the next shot, his arms are not visible at all. It changes between these two differing shots throughout the closing end of the dance routine. (00:10:10)
Continuity mistake: After the Cat has performed his dance routine, he begins to smoke a cigar and puts it down. The shot cuts to the ground controller, but when the shot cuts back to the Cat, the cigar is back in his mouth and has already been smoked. (00:10:30)
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.