Continuity mistake: At the end of episode one, when the Doctor and Taron spray paint onto the invisible Dalek, they use two different colors. At the start of episode two, the Dalek is suddenly black and painted on all sides.
Visible crew/equipment: In episode four, the Dalek chasing the heroes up the ventilator shaft is supported by strings.
Visible crew/equipment: As The Daleks plan to release bacteria into the atmosphere, a crew member is reflected in the glass box containing the bacteria.
Revealing mistake: Jo is hit by a rather large rock. Katy Manning visibly winces before it strikes (and bounces off lightly).
Audio problem: In the first scene with the Dalek Supreme, the lights on its dome are way out of synch with its speech.
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.
Visible crew/equipment: At various points in the story, the pots for the plants of the Spiridon jungle are visible. Episode two has a couple of noticeable moments, when Codal is captured and when the Doctor is led away by The Daleks.
Continuity mistake: When Wester - an invisible Spiridon - is treating Jo's arm, his shadow can be seen.
Continuity mistake: In episode five, Jo's hairstyle changes. She has one hairstyle in the bulk of the episode, which was filmed in the studio. And a different one during the "Plain of Stones" scenes, which were shot on location.
Revealing mistake: In episode 5, Codal discovers that what he thought was Taron is an invisible Spiridon. However, there is a glimpse of the actor inside the fur costume as he attacks Codal.
Visible crew/equipment: In episode five, when Taron knocks out the Spiridon, you can see a BBC camera in the foliage behind him.
Continuity mistake: In the very first scene of the story, Jo is holding a gun as she opens the TARDIS doors, but when they come into the console room, she has no gun and is using both hands to support the Doctor.
Plot hole: 10,000 Daleks sounds impressive but it wouldn't be enough to invade a planet, let alone an entire galaxy.
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