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.
Other mistake: One of the natives putting the captured Seaview personnel into the cave is wearing laced up sneakers. (00:36:25)