Revealing mistake: When Lister and the Cat drop the gravestone and break their feet, you can see that it does not land anywhere near Lister's left foot. (00:26:55)
Revealing mistake: When Rimmer puts the engaged blindfold on and sits on the toilet, he doesn't take his trousers down. (00:03:50)
Revealing mistake: Holly's night cap is in front of the edges of his monitor. It should fade into the white border of his screen. (00:05:25)
Revealing mistake: When Kochanski is shot with the spear, the padding that gives the impression the spear is through her leg is visibly bulging in her trousers as ahe pulls on the rope. (00:26:50)
Gunmen of the Apocalypse - S6-E3
Revealing mistake: When the crew are trying to figure out how to save Kryten before going into the game, the Cat says 'if not, why not?' You can see Lister mouth the line. (00:15:25)
Gunmen of the Apocalypse - S6-E3
Revealing mistake: When Rimmer throws a cowboy over the bar, it wobbles. (00:21:35)
Revealing mistake: During the car chase, the box Rimmer is sitting on keeps moving. (00:21:25)
Gunmen of the Apocalypse - S6-E3
Revealing mistake: When the Cat says 'not if you believe those lying cartoons' you can see Lister mouth the line. (00:09:50)
Revealing mistake: After landing on Earth, Rimmer and Kryten are standing on land. When Kryten asks "What is this place?", a car can be seen driving forwards in the far background, even though everything in this version of Earth is supposed to work backwards. (00:06:15)
Revealing mistake: When the ship crashes into the snow planet, a wire can be seen attached to it as it crashes.
Revealing mistake: When Lee Harvey Oswald is preparing to shoot JFK on the fifth floor of the book depository, there is a shot of him from the side where he points his gun out of the window. To his left are a numerous boxes belonging to the book depository. Many of the boxes have "books" written on them, and some have hand written numbers on them. Later in the episode, the crew go back in time to send Oswald up to the sixth floor, but in the side view shot where he points his gun out of the window this time, the boxes are completely identical to the ones used on the fifth floor. The same set was likely reused.
Revealing mistake: When Legion places the hard light in Rimmer's light bee, it is noticeable that the hard light does not go inside the device. It is placed more to the area beside it. (00:09:55)
Revealing mistake: When Lister hits Legion over the head, his mask falls off. In the shot that shows Rimmer, Cat and Kryten in the foreground sitting at the table and Lister and Legion in the background, Legion's face can be seen and it is apparent that it is not the combination of the four that is his face, but in fact the actor's real face. (00:21:15)
Revealing mistake: With the Matter Paddle, Kryten transports into the sleeping quarters, and then transports onto the bunk. When Kryten transports onto the bunk, the Cat's position on his chair visibly alters on screen, showing where the scene was edited to make Kryten appear as if he transporting. (00:03:15)
Revealing mistake: When Kryten transports the Matter Paddle back to Red Dwarf, the position of Kryten's hand visibly alters on screen, revealing where the scene was edited to make the paddle appear as if it had transported. (00:06:30)
Revealing mistake: When it is revealed that the DNA modifier has made Lister smaller, Rimmer, Cat and Kryten all have shadows cast on the floor, but Lister does not. (00:25:25)
Revealing mistake: When Rimmer is piloting Starbug in Lister's body, there is a shot of Starbug spinning in circles. This is a shot that was taken from S3 E2 Marooned, of Starbug crashing after colliding with the asteroid. The only difference is the planet in the background has been changed. (00:22:10)
Revealing mistake: During the chase on the moon, there is a shot from in front of Starbug crashing into an asteroid. About twenty seconds after this, the exact same shot of Starbug crashing into an asteroid is been repeated a second time, when the ship crashes. (00:23:20)
Revealing mistake: Crawford goes through the teleport to transport herself to the Space Station. But in the next shot, Crawford can be seen quickly leaving the shot as if she's still there. (00:23:05)
Revealing mistake: When the future echo Rimmer leaves the drive room and the actual Rimmer walks in, there is a visible line caused by the split screen effect, done to show two Rimmers onscreen at the same time.
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.