Revealing mistake: Watch the Mandrells closely, especially in the later parts of the story: one of them seems, at one point, to have forgotten to zip up the back of his costume.
Revealing mistake: In the very first shots of this Doctor Who story, it is obvious that the "Empress" Spaceliner is a model - you can even see the stick that holds the model in place.
Revealing mistake: Geoffrey Hinsliff (playing Fisk) accidentally refers to Tryst as "Fisk" at one point.
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