The Monster of Peladon - S11-E4
Plot hole: The temperature of the air being blown into the mines is controlled from the communications room when the Doctor needs to knock out The Ice Warriors. But conveniently, the ventilation system is controlled from the refinery when Eckersley needs to suffocate the miners.
The Monster of Peladon - S11-E4
Continuity mistake: When opening the door to the refinery, the Doctor leaves his sonic screwdriver on top of the panel. However, a few seconds later, when we next see the panel, the sonic screwdriver has disappeared.
The Monster of Peladon - S11-E4
Continuity mistake: In episode six, the Doctor is using the Aggedor statue to fight The Ice Warriors. The door to the refinery was partially destroyed by The Ice Warriors earlier. But in every shot of Aggedor appearing or re-appearing, the door can be seen intact at the edge of the shot.
The Monster of Peladon - S11-E4
Revealing mistake: The mines are fairly obvious set constructions. The floor is flat with some sand thrown on. In addition, gaps can occasionally be seen between the floor and the walls or the floor and boulders.
The Monster of Peladon - S11-E4
Revealing mistake: In the climactic fight at the end of episode four, the face of the Doctor's stunt double can be seen.
The Monster of Peladon - S11-E4
Continuity mistake: In episode six, the same extra is killed by both Azaxyr in the ambush and by Eckersley later on.
The Monster of Peladon - S11-E4
Revealing mistake: Near the end of episode six, when Aggedor is falling dead to the ground, the clothes of the man inside the costume can be briefly seen in a gap between Aggedor's leg and foot.
The Monster of Peladon - S11-E4
Visible crew/equipment: When Azaxyr is setting his ambush for the miners in episode six, a studio light can be seen through a gap in the wall.
Planet of the Spiders - S11-E5
Revealing mistake: In episode three, when Tommy peers into the room where the Doctor and Sarah are talking to Cho-Je, the camera moves forward - and bumps into a wall with an audible thud and noticeable jerk.
Planet of the Spiders - S11-E5
Continuity mistake: In episode two, Lupton steals a boat, throwing the pilot into the water. Moments later, we see him struggling with the pilot again - who is perfectly dry.
Planet of the Spiders - S11-E5
Revealing mistake: At the very beginning of episode four, the thin pole moving the queen spider can be seen.
Planet of the Spiders - S11-E5
Revealing mistake: In episode one, when a psychic wind is blowing everything all over the Doctor's lab, look for the hatstand standing steady as a rock.
Planet of the Spiders - S11-E5
Revealing mistake: A bad CSO match up occurs in episode one, when Clegg is making the breakfast tray float across the room. The Brigadier is looking at a point some distance from the CSO'd tray.
Planet of the Spiders - S11-E5
Revealing mistake: When Mike and Sarah are in Mike's car going to the monastery, the car swerves off the road and Mike is replaced by a stunt man.
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