Other mistake: As Virgil prepares to clear the wreckage of the tower from the rescue area using the Firefly, Scott tells him that he will go over to Thunderbird 2 to prepare the Mole for tunneling. The Tower Controller then says to Scott, "I've got a fast car ready for you outside" without moving his lips.
Thunderbirds (1964)
1 other mistake in City of Fire - chronological order
Starring: David Graham, Ray Barrett, Peter Dyneley, Shane Rimmer
Revealing mistake: When the dummy plane is shot out of the sky by the fighter pilot, a piece of the plane shoots off into the top left of the screen and bounces off the sky background. (00:23:05)
Trivia: Although he is the main villain, the Hood appears in only six episodes throughout the entire series.