Revealing mistake: In several episodes, but mostly in series 6, we see lots of profile camera shots of just Lister and The Cat at the front of the cockpit in Starbug. Quite a few times you will see Lister mouth The Cat's lines so he knows when to start speaking and what to say.
Revealing mistake: After the Cat's dance, Lister says 'we are outta here' and pulls the level, at which point the crew all fall back as if Blue Midget had rushed forwards. However, in the model shot of the ship it shows it scraping its foot on the floor before it runs forwards, meaning the crew should not have fallen back in their seats. (00:10:50)
Revealing mistake: In the captain's office, the words 'Medical bay' have been painted on the wall. This was near The End of the episode and can be seen over Rimmer's shoulder while they are talking in the drive room. The set was obviously doubled with the medical bay, as the captain's office is not used in this episode. (00:23:25)