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.
Other mistake: Throughout the show, reference is made to Rimmer's light-bee, a solid unit that buzzes around projecting his holographic image. Yet he constantly walks through things without any difficulty. Not physically possible if there is something solid in his form.
Other mistake: Holograms are often seen passing through physical objects, walls, furniture, and other people. Yet, they have a physical object generating the hologram: their light-bee. This would not be able to pass through other solid objects.
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.