Plot hole: Kryten explains that the quantum skipper must be recharged after every use, and the time this takes must be must be taken into account. This is an important plot device the first time Rimmer uses it, but it is conveniently forgotten for the rest of the episode.
Suggested correction: Kryten said what he believed to be true based on purely theoretical work. No evidence is presented that he'd tested the skipper "for real." Its ability to hold charge on subsequent jumps was better than he'd anticipated.
Read the posting again. "This is an important plot device the first time Rimmer uses it..." It was not only stated but demonstrated that the time skipper must be recharged each time it is used.
Watch the episode again. The need to recharge the skipper after every use was stated but not demonstrated.
Plot hole: At The End, Kryten, Rimmer and Lister are in a lift facing off six gelf shapeshifters - two copies of each real person, in a Mexican standoff. Nobody knows who to shoot, as they might shoot the real person instead of the shapeshifter. But the real people know they're real - all Lister has to do is shoot the two fake Listers, Rimmer shoots the fake Rimmers and Kryten shoots the two fake Krytens, problem solved. Not to mention Lister is now a soulless, unfeeling killing machine. Earlier he shot and killed a shapeshifter who could well have been Cat - he didn't know it was a shapeshifter and by his own admission he didn't care. We have already seen how fast on the draw he is - why didn't he just open fire on the six shapeshifters, Kryten and Rimmer in order to ensure his own survival?
Suggested correction: The point of a Mexican standoff is no one is in a position to shoot first for fear of being shot themselves. We're told the shapeshifters have no problem killing each other, so as soon as the real person starts to shoot, everyone may start firing, which could result in a real person being killed. Additionally, the only time all 9 are pointing guns at each other is in the lift. Before that, it's 3 groups of Listers, Krytens, and Rimmers, so no one is facing off with their shapeshifters. The only safe way to shoot the 6 shapeshifters would be to do it at the same time, and there's no way Lister, Kryten, and Rimmer could coordinate that. And, like all Mexican standoffs, it can only be resolved from outside help.
Factual error: Kryten tells everyone that the matter paddle transmits matter in digital form from one place to another at the speed of light - he is very clear on this point. He then locates Waxworld, which is 200,000 light years away. Okay - so when they use the matter paddle to transmit themselves to Waxworld, why doesn't it take them 200,000 years to get there?
Suggested correction: Kryten says that the paddle sends them via subspace, so they will reach it almost instantaneously (rewatch the scene, he never says they'll travel at lightspeed).
Plot hole: Right after the shrinking boxers scene, Kryten says the small boxers are missing from the bunk, but you can see them right in front of him. (00:10:00)
Suggested correction: I've just watched this scene. You're mistaken. The boxers aren't visible when Kryten turns back to the bunk. The trunks were bright red. The only red thing visible in the scene where Kryten is looking at the bed is the "no smoking" sign, which is on the side of the bed, right in front of him.
Character mistake: Surely, a know-all like Kryten would know that although lemons are not native to the Middle East, Babylonian traders imported lemons into what was then Judea some five hundred years before Christ was born, and by 4BC, they were quite common in the area, albeit as a pricey imported delicacy. The Dwarfers wasted half of their epic overland trek.
Suggested correction: Kryten is known to delete his unnecessary cache files to create more memory space. It's not unreasonable to assume that whilst he could have known at one time, he'd since deleted that information.
Creating deus ex machina explanations for mistakes does not invalidate them. I could argue that Kryten would have done a little research before he set off on a 7,200 km journey, but that isn't featured in the episode either.
Other mistake: Unfortunately the whole basis of the show is one big factual error. Throughout the series we see that Red Dwarf sustains damage from collisions, explosions, and so on. Most important of all, the rocket engine nozzle - surely made from the strongest materials available - has been punctured by some kind of impact. The systems require constant maintenance by humans (painting, repairs, etc), so skutters are not enough by themselves. So, we know that Red Dwarf is not made of some sort of fictional, indestructible materials, it is made of the kind of metals, plastics and other construction materials we build space shuttles and the like out of nowadays. So, after three thousand - never mind three million! - years the whole ship would be a clump of useless, corroded junk. The rubber and plastics in seals, electronic components and furniture would have crumbled to powder. The electronics themselves would have failed after a few hundred years at most. Metals in contact with liquids in pipes or reservoirs would have oxidized, and even the oxygen in the air would have been corrosive after that amount of time. Red Dwarf is not immune from the effects of long term decay and deterioration - if it were when Lister was released from stasis he would have found rooms full of relatively intact dead bodies instead of piles of crumbled dust. After three million years in space Red Dwarf would have been a pile of scrap, fatal to anyone going near it; subject to slow, subtle but constant radioactivity in space, after three million years it would be hotter than the inside of a working reactor.
Suggested correction: We don't have enough detail on what the ship is made out of. It taking damage doesn't mean it's made from current materials; it could use new materials with unknown properties. Eg, when the polymorph goes through a metal pipe, the tap distorts then reshapes. Seemingly impossible, but it happens. Rubber and plastics may not pulverize. Metals could be oxidation resistant. Advanced filtration might keep air fresh indefinitely. Technology that we can't imagine today keeps everything working and safe.
Other mistake: In the picture of the cat wars between the Red Hats and the Blue Hats, the hats are orange instead of blue. (00:19:00)
Suggested correction: Cats are partly colour blind.
Revealing mistake: At the start in the cockpit of Starbug, the green screen behind Lister is visible instead of the painted starfield that should be there. (00:02:35)
Suggested correction: That is because Starbug is parked inside Red Dwarf at the time, and the stars wouldn't be visible.
Continuity mistake: Just after The Inquisitor is frozen when Lister and Kryten switch gauntlets, the glove gets onto Kryten's hand in one camera cut. (00:24:30)
Suggested correction: He's holding the gauntlet in his hand, but the angle of the camera makes it appear that he's wearing it.
Continuity mistake: In the forest, Lister and the Cat take a poster off a tree. They then show it to the man who gives them a lift. The poster is different to the one in the forest. (00:16:05)
Suggested correction: If you look at 00:13:47, you'll see that the closest tree has an odd poster. The other trees have the poster that they showed to the man that gives them a lift.
Emohawk - Polymorph II - S6-E4
Revealing mistake: Both Ace and the Emohawk get sprayed with the liquid Dyllinium, yet only the Emohawk becomes paralysed. (00:26:55)
Suggested correction: Ace is a hologram. Even though he is hard light, he cannot be harmed. Which is why he was able to jump on the grenade and not be harmed. So the gas spray wouldn't have harmed him either.
Plot hole: As the luck virus gets you what you want, it should not have cured Lister of the sexual magnetism virus when Kochanski was all over him. (00:16:25)
Suggested correction: According to the Red Dwarf Fandom page, "The Sexual Magnetism virus makes the infected irresistible. The only known anti-virus is the Luck Virus, which was discovered by accident by Dave Lister." Granted, it doesn't seem to make sense, but apparently that's just the way it works.
Plot hole: The man the crew find stampeded to death had been lying in the road for a year, yet he had not began to decompose. (00:17:50)
Suggested correction: There's nothing stating that the body had been lying in the road for a year. Rimmer says it looks like the man was trampled to death in some kind of stampede, but it isn't confirmed if that's how he died (Rimmer is often wrong about many things), or when it might have happened.
Plot hole: In the last series, a point was made that the time drive is not a teleporter, so can only send them backward and forward in time in the one location (Deep Space). So in this episode, how can they now travel to Earth with the same device?
Suggested correction: With the merging of the two universes, the time drive ended up with the faster-than-light drive from the other universe (which is also how Starbug ended up bigger).
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.
Plot hole: At the start of the episode, on a shelf in the sleeping quarters is one of Rimmer's Army De Nord figures, which were all burned in Marooned in series 3. (00:00:40)
Suggested correction: Obviously, he has more of the figures than those that were in the chest; it's never stated that he doesn't, and he missed at least that one when packing.
Revealing mistake: When Baxter puts the Cat's head in the drinks machine and says hot bovrill, Kryten can be seen mouthing the line behind him. (00:22:20)
Suggested correction: Kryten is not mouthing the line "Hot bovril." He is just moving his mouth slightly up and down, which coincidentally happened to occur when Baxter was saying the line.
Plot hole: Allman does not remember his trial when The Inquisitor erases him, yet Lister and Kryten do remember their trial when they are sentenced. (00:01:20 - 00:13:30)
Suggested correction: Maybe Allman just had a bad memory.
Other mistake: When Rimmer tries to silence the vending machine, he covers up the input microphone with stickers instead of covering the speaker just above it. (00:05:05)
Suggested correction: This isn't a mistake. There's no evidence that the speaker is just above the microphone (the "speak here" grill). The vending machine tells Rimmer to take his hand off its speaker when his hand is over the "speak here" grill. This suggests that the grill covers both the microphone and speaker.
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.