Delta and the Bannermen - S24-E3
Revealing mistake: The bodies lying on the ground during the initial battle are rather too obviously rubber dummies rather than real people.
Dragonfire - S24-E4
Revealing mistake: At several points in the story the 'huge heavy ice cliffs' get blown fractionally upward by people running past them, showing that they are made of very thin, very light plastic.
Revealing mistake: When Ace and Susan are sitting underneath the huge pipe about to be executed by the Fondant surprise, it's obvious that the actresses aren't sitting directly underneath the pipe, but slightly behind it.
Revealing mistake: In episode one, as the Doctor is repairing the buggy, one of the patrol runs on too soon, realises that he's come in ahead of his 'cue', and runs back.
Revealing mistake: When the Doctor taps the ice crystals, they wobble instead of breaking.
Revealing mistake: When Ace is being attacked by the Haemovores, she strikes one of them on the head, causing its mask to go up and revealing part of the actor's neck.
Revealing mistake: When Fenric (having possessed the body of Judson) knocks over the chess pieces on the board, watch one piece (The King) in particular. You can see a 'hinge' made of white sticky tape attached to the board and the base of the chess piece, presumably there to stop the chess piece rolling away onto the floor.
Revealing mistake: The shot of the two motorbikes colliding with each other and exploding into flames is very unconvincing. Watch carefully, and you can "see the join" where a shot of the two motorbikes passing each other (and NOT colliding) is replaced by a "staged" fiery explosion.
Answer: It was never destroyed on-screen; it was intact at the end of the TV movie, and destroyed by the start of the 2005 series. It was destroyed in the novel "The Ancestor Cell," but in a completely different manner to what happened in the series.
DaveJB