Continuity mistake: At many points in this story there are problems with the costume that Zoe is wearing...the zip is often jammed part or all the way open. Not only does this leave most of her back exposed, but the position of the zip tends to change position during scenes, as while off camera Zoe tries to pull the zip back up, only for it to open up again minutes later. (It is a little unkind to say it, but possibly the costume was a little bit too tight for Zoe, causing it 'self unzip'?).
Plot hole: When Jamie and Cully go on the offensive, Jamie lures a quark away from a drilling site into a narrow valley, then Cully drops a boulder onto it. Yet when we see the crushed quark, it is next to a drill, on flat land.
Other mistake: When the Doctor pulls Zoe and Jamie back into the TARDIS, look at the scanner screen. It has the words 'Producer Peter Bryant' written on it.
Other mistake: The Master says he wrote 5,000 words a week for 25 years and Zoe says "but that's over half a million words." Yes it is, to be exact, six and a half million words. (5,000 x 52 x 25 = 6,500,000).
Continuity mistake: This story starts off where the previous story ('The Dominators') finished, but Jamie says something completely different to alert the Doctor to the approaching lava flow.
Continuity mistake: Near the end of episode three, Jamie starts to read the printout. At first, he is reading the printout the right way round. But when we next see him, he seems to be reading it upside down. Then the third time we see him, he is back to reading it correctly (right way up).
Continuity mistake: When the TARDIS breaks apart and the console sent spinning off into space, Zoe is lying on it. In close-ups she lying on her left side facing towards Jamie (who is opposite), but in the distance shots done with small models, she is lying on her right side facing away from Jamie.
The Invasion - S6-E3
Audio problem: The first victim of the hypnotic signal stops walking when he hears it, but the sound of his footsteps continues for several seconds afterwards.
The Invasion - S6-E3
Revealing mistake: The Cyberman that falls from the roof in the final episode is obviously an empty costume. (This is another example of a mistake being repeated from an earlier episode. See the earlier story "The Tomb of the Cybermen" for a note about the same 'revealing' mistake happening).
Visible crew/equipment: Episode 5, while Zoe and Jamie are at the Weather Control Station, when they hear the Ice Warrior approaching they both hide, and the actor's T-mark is visible on the floor. (00:18:00)
Revealing mistake: When Slaar discovers the video link is operational and being viewed on Earth, in the closeups of Slaar we can see the edge of the reptilian mask and the actor's real human neck. (00:20:40)
Continuity mistake: Patrick Troughton's sideburns keep appearing and disappearing, depending on whether what is being shown is location filming or studio.
Revealing mistake: When Jamie is wrestling with one of The Ice Warriors in a storage room, one of them gives the wall an almighty knock and it nearly falls down.
Visible crew/equipment: While The Doctor and Zoe are on the SIDRAT, The Doctor expresses hope to get the hang of its controls. When the SIDRAT materializes, in the shot facing the door as The Doctor pokes his head out to exit, the camera turns toward the right and there's a reflection of the moving camera and the camera operator walking behind the camera, at the right side of the screen. (00:08:25)
Revealing mistake: Episode 6, while in the barn Von Weich asks Moor (played by David Troughton, son of Patrick, who plays The Doctor) to retrieve the monocle in his pocket. Then, when Von Weich continues with his plan, in his closeups we can see a vertical piece of mesh tape over the actor's right eye. (00:13:05)
Plot hole: Despite being asked to memorise all the locations and war zone commanders, Zoe's photographic memory lets her down: her first words to the Mexican leader are 'Who are you?'.
Continuity mistake: The end of episode 7 does not match the reprise of the story at the start of episode 8. The Doctor, Security Chief and guards file into the SIDRAT in a different order.
Factual error: The Doctor meets Jamie at a time after the Battle of Culloden. But here Jamie says he met him in 1745. Culloden took place in 1746.
Revealing mistake: When the resistance are storming the landing bay, one of them punches at least a foot to the right of a guard's face, but he still collapses.
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