The Dalek Invasion of Earth - S2-E2
Continuity mistake: The paint on the Black Dalek changes between episode 2 and 3.
Continuity mistake: In episode one, Vicki passes her hand through a museum display, making the point that the crew cannot interact with their environment. A moment later, she bumps into a statue, making it wobble.
Continuity mistake: When Frankenstein's Monster begins chasing The Daleks, he's wrapped in bandages. When he catches The Daleks in the room with the TARDIS, he's suddenly wearing a suit.
Continuity mistake: When the Doctor and Ian encounter the Frankenstein monster in episode four, you can see a Dalek behind them, even though it's long before The Daleks arrive in this time zone.
Continuity mistake: In episode four, when the Doctor and Ian return to Frankenstein's lab, the monster is lying on the table in the opposite direction from when they left.
Continuity mistake: Towards the end of episode 2 it's nighttime, but when Ian and the Doctor lure the Dalek over from the TARDIS, and when it falls, it's daylight.
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