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: Every time Thunderbird 3 is used during a mission, members of the Tracy family enter it by being lowered on the settee onto a mini rail system, which takes them to Thunderbird 3's hangar before a pole raises the settee into the ship. However, during the initial descent, there is usually an empty settee that passes behind the descending one carrying the impending Thunderbird 3 crew, to fill in the resulting hole in the floor. If the ascending one passes behind the descending one then there is no way that it could fill that hole as it would be too far back.
Other mistake: Some scenes in this episode feature portraits of Jeff Tracy's sons in their civilian clothing. This is only done on "Operation Cover Up" to disguise all evidence of the International Rescue organisation when a visitor comes to Tracy Island, but there were no visitors to the island during the episode.