Character mistake: When Rimmer, Cat and Kryten go down to the cargo hold to search for the Polymorph, Kryten says "It's here" and "somewhere", but he delivers the line in an English accent and not in his robot voice. (00:13:15)
Timeslides - S3-E5
Character mistake: The assassination attempt on Hitler in 1944 was in Rastenburg, not Nuremberg as stated in this episode. (00:08:50)
Character mistake: After the crew realise that the matter paddle has made 2 copies of Red Dwarf, Kryten says something along the lines of, "When I threw the machine in reverse...", but it wasn't actually him who threw the machine in reverse, it was Lister. (00:06:55)
Character mistake: Rimmer asks Kryten to make the new computer blonde. When the computer launches, the computer's hair is brunette. (00:07:30 - 00:08:45)
Suggested correction: It's possible that, rather than making a mistake, Kryten simply ignored the request.
Character mistake: Upon hearing that Lister, Kryten, Cat, and Rimmer have travelled from Albion - England - to India, the woman in the market expresses surprise that they have travelled "halfway across the known world" just to buy lemons. In 23 AD, travelling from England to India was all the way across the known world. The Americas, Australasia, and China would have been completely unknown to a first-century Indian woman.
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.
