Genesis of the Daleks - S12-E4
Continuity mistake: In episode 6, when the lead Dalek is saying 'Pity? I have no understanding of the word' the lights on the top of its dome stop working. They start working again in the following shot. (00:21:00)
Revealing mistake: In episode 6, when the Brigade Leader shoots the Primord Stahlmann, he falls down but no bullet holes are made in his costume. Thanks to Producer Barry Letts for spotting this one on the DVD commentary. (00:17:00)
The Caves of Androzani - S21-E6
Factual error: Sharaz Jek's monitor that displays the tunnels and his androids is inaccurate. The white blobs are, as we learn later, supposed to represent his androids. He tells the Doctor that the green area is held by the army, yet on the screen the green area is populated by androids, so they could not have had control.
The Caves of Androzani - S21-E6
Revealing mistake: When Stotz cuts a hole in his ship's door, you can see that the inside of it is made of white polystyrene. They painted the outside of it but obviously forgot about the inside. Also listen to the sound it makes when Stotz punches the hole through - it sounds exactly like polystyrene.
The Sea Devils: Episode Two - S9-E10
Continuity mistake: In episodes 2 and 3, watch the clock on the wall in the Master's quarters. When the Master pulls a gun on the Doctor and the Doctor quickly pulls the door shut, the clock shows ten minutes to three. In the next episode, after the swordfight is over and the Doctor is being led out by the guards, the clock now shows approximately eight minutes after twelve.
Destiny of the Daleks - S17-E1
Plot hole: The Daleks spend a lot of time and effort mining down to where Davros is, despite the fact that there is a window on that level and Davros is on the ground floor.
Plot hole: Jo is surprisingly skeptical about the TARDIS being able to move, considering she saw it dematerialise in the last episode.
The Dalek Invasion of Earth - S2-E2
Continuity mistake: The paint on the Black Dalek changes between episode 2 and 3.
The Dalek Invasion of Earth - S2-E2
Visible crew/equipment: When the rebels attack the Dalek saucer, a Dalek asks what sector the prisoners were taken from, and in the bottom left hand corner a giant boom mike comes into view.
The Dalek Invasion of Earth - S2-E2
Revealing mistake: In episode 1, one of the windows on the TARDIS is leaning in, but by the time we get to episode 6 it has managed to fix itself. Also when the bridge falls down you can see the poster through the gap, showing that there is no back to the TARDIS.
Revelation of the Daleks - S22-E6
Visible crew/equipment: In the first scene of episode 2 you can see a member of the crew casually walking in the background.
Visible crew/equipment: In the first scene of episode two, as the Doctor collapses on the ground, a person can be seen moving in the back of the set.
Revealing mistake: During episode three, in the mining area, just before the city's root appears, the tracks on which The Daleks move can be seen.
The Caves of Androzani - S21-E6
Factual error: When the Doctor is trying to land the ship, from the video screen it appears that they are moving towards the planet way too fast to make such a safe and quick landing. Also, the ship doesn't seem to have even penetrated the planet's atmosphere yet it lands seconds later.
Revealing mistake: Perhaps criticizing the special effects is unfair, but the extremely obvious use of toy tanks and a rag-doll Sarah in certain scenes is one of the worst examples in the history of the show.
The Monster of Peladon - S11-E4
Revealing mistake: When the Doctor and Sarah arrives in episode one, they leave the doors of the TARDIS open and the empty inside of the TARDIS can be seen.
Other mistake: After Linx plants his flag in the ground claiming Earth, Irongron and Bloodaxe look offscreen for no reason, as though the shot is finished.
Plot hole: A line of dialogue in "The Curse of Fenric" indicates that the Russians planned to make their escape by "going to the North Way", in other words, escaping to Norway. However, the story is set in the summer of 1943, when Norway was under Nazi occupation. It would not be a smart idea for any Russian military personnel to head for Nazi-occupied Norway.
Continuity mistake: Patrick Troughton's sideburns keep appearing and disappearing, depending on whether what is being shown is location filming or studio.
Plot hole: The energy weapons in this story fire a series of small red bullets, which cause numerous problems. For a start, the guns appear to have seven chambers, yet the bullets start from the same point; as they are separate bullets, surely the most minor of movements would mean they wouldn't emerge in a straight line. Later, when the Doctor steals a cart, the bullets are coming quite a distance towards the screen but the bullets don't get any bigger. Also, in the same scene, the Doctor passes through the area they seem to be travelling, yet the bullets just continue to pass in front of him.
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