Other mistake: When Cat picks up the can of Leopard lager which is invisible to Lister, he shakes it, pops the cap and sprays Lister with foam. The foam is visible but the can remains invisible, and that makes no sense. If we are seeing the scene from Cat's point of view the can and foam should both be visible, and if it is from Lister's then neither should be.
Other mistake: When Lister (in Rimmer's body) pleads the Cat to lend him his body, he says "how else can I pilot White Midget?" In the next scene, the Blue Midget is being piloted, and White Midget was originally abandoned for Starbug. (This mistake was admitted by the crew). (00:21:45)
Other mistake: At the start of the episode, there is a spoof Star Wars-type caption, which spools up the screen very quickly. Too quickly to be read, in fact... which may explain why few people have noticed that the last line of the caption, "And now the Saga Continuums...", is written twice. (00:00:20)
Other mistake: When the meteor hits Starbug, there are no stars outside the front of the ship at all. (00:07:20)
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)
Other mistake: Kryten places Rimmer's light bee on the floor, then begins the process of reinitialising him. As the process finishes and Rimmer looks at Lister (who looks away), the light bee, which should be hovering within his torso projecting his image, is still visible on the floor between his feet. (00:06:00)
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)
Other mistake: At the start of Rimmer's exam, the invigilator orders the students to "turn over their papers and start". Rimmer reads one side of the paper, then turns it over to read another question. The back of the paper should have been blank as otherwise there would be no point asking the students to keep the papers face down before reading the questions. (00:15:30)
Other mistake: When Legion stabs his left hand, everyone grabs and shakes their left hands - except Lister, who grabs and shakes his RIGHT hand. (00:22:40)
Other mistake: When Lister reads Rimmer's diary, he reads the first entry, then his aunt's birthday in July and then the entry for Gazpacho Soup Day in November. Each time he looks for the next entry he flicks though the pages, yet every time he reads, it is from the start of the diary. (00:15:25)
Other mistake: The tax letter and Rimmer's mother's letter are both already opened before Lister takes the letters out. As there is no one else aboard Red Dwarf, the letters would not have been checked by anyone so they should still be sealed. Also, not all of the letters are already open, just the two that Rimmer receives.
Other mistake: Kryten sees Ace's ship before it materialises. (00:12:55)
Other mistake: The milkshake and toffee crisp come out of a different vending machine to where they were ordered. (00:01:50 - 00:06:55)
Other mistake: Rimmer's badge of rank is missing from his short sleeved uniform. All other uniforms in the series have the badge. (00:15:10)
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: When Lister inadvertently sets off the Auto Destruct sequence, the computer voice says the ship will detonate in 15 minutes. The computer then says "the ship will detonate" every five seconds followed by how much time until detonation, but the time in which the computer says this is inconsistent. Two seconds after the computer says 15 minutes, the computer says the ship will detonate in 14 minutes 55 seconds. Ten seconds after saying that, the computer says the ship will detonate in 14 minutes 50 seconds. (00:01:50)