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 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.
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 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.
Resurrection of the Daleks - S21-E4
Revealing mistake: When the Doctor is shooting the Dalek creature hidden under the coat, he is obviously using blanks because when you see the coat there are no bullet holes in it.
Visible crew/equipment: After the Doctor recovers from his coma, he gets up and stands at the console. A reflection of a crew member can be seen in the shiny part of the central column.
Plot hole: The Bandrils not only know of the Time Lords but are capable of connecting to them, yet the Bandril are barely capable of space travel and can't produce their own food. So, the Bandrils are not very technologically advanced it seems, so why do they have ties with the High Council of the Time Lords? And how does either party benefit from such an association?
The Daleks - S1-E2
Revealing mistake: The Dalek that Ian hides from in Episode Seven has a bad castor. The flopping of one of its wheels is audible. (00:08:20)
Plot hole: It is highly unlikely that the discovery of a dead down-and-out's body in an empty warehouse would be reported in a national newspaper, especially as the discovery had to have been made when the newspapers were already being printed.
The Dalek Invasion of Earth - S2-E2
Visible crew/equipment: As the two prisoners join the Doctor and Ian, the camera follows them and you can see the heliport set through the Dalek saucer.
The Dalek Invasion of Earth - S2-E2
Audio problem: When the Dalek says to give the Doctor and Ian the test, it cuts to the prison cell where you can hear a Dalek voice that gets cut off.
Revealing mistake: When the Doctor and Leela are put in Uvanov's cabin to await questioning there is a shot of a robot listening to them in which you can see the actor's neck.
Revealing mistake: K-9 has a bit of difficulty in the mansion in episode two. The thread pulling him is visible and Baker has to help him over a flagstone.
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