Revealing mistake: Throughout Series 2 Eve's reptilian hand is a glove made out of rubber and you can tell whenever she bends her wrist and the "skin" twists and wrinkles. An obvious example of this is in Episode 6 when she has finished going through "Accelerated Learning" and removes the listening device, bending her wrist and the glove in the process.
The Demon Headmaster (1996)
1 revealing mistake in Season 2 generally - chronological order
Starring: Terrence Hardiman, Frances Amey, Gunnar Cauthery, Thomas Szekeres
Episode #1.2 - S1-E2
Revealing mistake: Towards the end of the episode when Dinah, Lloyd and Harvey are walking to school you can see a man and a woman stood at the end of their driveway watching filming. (00:19:28)
Trivia: The music used for the Octopus Dare computer game is an 8-bit rendition of the show's main theme tune.