Factual error: On the night of the Hudson Building fire, the Auto Date Fixer in Commissioner Garfield's office reads 12/7/65. The next day, it reads 13/7/65, illustrating attention to detail on the part of the set decorator. Unfortunately, this overlooks the American convention for the month numeral to appear first. In the US the convention is month/day/year, in the UK the convention is day/month/year. So, either the first date should read 7/12/65 (July 12th) with the next day as 7/13/65, or the second date should read 12/8/65 (December 8th).
Plot hole: When Jeff Tracy contacts Lady Penelope, it is 10:00am in England, yet it is already daylight on Tracy Island in the South Pacific and Alan, Gordon and Tin-Tin have been out fishing for some time. (It is later established in the 1966 "spin off" movie "Thunderbirds Are Go" that there is a five hour time difference between Tracy Island and England. So, using that as a guide, when it's 10am in England, it should be 5am on Tracey Island.)
Revealing mistake: When the Plutonium store doors are blown off by the Jet-Air Blaster on the Laser Cutter Vehicle, you can see a length of string pulling the doors off from the inside.
Revealing mistake: In a close-up of the hitchhiker putting the bracelet on Prescott's wrist, you can see the bracelet is not locked on.
Visible crew/equipment: In a shot of the camera moving through the castle, the shadow of some studio equipment is moving down one of the pillars.
Continuity mistake: When the stranger waves at Prescott, telling him to slow down, we cut to Prescott in his car and you can see that the car has a windscreen, but when the car stops near the stranger in the next shot, the windscreen is missing.
Continuity mistake: When the laser vehicle leaves the pod and enters the plutonium store, you can see the cockpit has a windshield, but when Scott tells Virgil "We're gonna have to work fast", we cut to Virgil, and the windshield has disappeared.
Continuity mistake: While Prescott, Dempsey and Kenyon are in the castle, there is a glass, a bottle and another glass (in that order diagonally) in front of Prescott. In a close up shot of him, the green bottle has move several inches to the left.
Continuity mistake: When Brains falls under The Hood's influence, he collapses, and between shots his glasses simply disappear. They are subsequently shown to have fallen off, but the action is not seen on screen: one moment the glasses are on his face and the next they have vanished.
Continuity mistake: When Thunderbird 2 launches Thunderbird 4, the number "4" on the puppet sized pod door in a close-up does not match that in the model scale long shot.
Continuity mistake: When we see the Professor unconscious by the cabinet in the caravan, there is a bottle of white formula next to him that changes position between shots.
Continuity mistake: When the Tracy family are sitting at the table eating their breakfast, there is a green cereal box on the table, but when Jeff says he is going back to the lounge to wait for Brains' call, the box has disappeared.
Continuity mistake: When Brains collapses under the Hood's influence, he has nothing in his left hand, but when the Hood takes off his mask, we see Brains again, and this time a blue stone has appeared in his hand.
Continuity mistake: When the Gray and Houseman Construction Company vehicle is moving along at the beginning of the episode, the launching pad is raised, but after a quick cut to the crew, we return to the vehicle and the pad is now lowered.
Revealing mistake: The raindrops on the faces of Eddie Houseman and his colleagues during the storm are disproportionately large.
Suggested correction: This is part of the art style of the show - the same reason everyone's eyes are so disproportionately large, it helps the viewer to see details that would otherwise be too small to spot.
Continuity mistake: In several wide shots of Thunderbird 1 and Eddie's tractor on the cliff, the yellow pins that were fired from TB1 earlier and the rock they were holding have disappeared.
Visible crew/equipment: When Tin-Tin responds to news of Scott's disappearance, a floor puppeteer's hand (with dirty fingernails) can be seen at the bottom of the screen lifting Tin-Tin from her seat.
Continuity mistake: In the pyramid, we see a closeup of Scott's hand grabbing the gun. The color of his uniform changes for a lighter blue in that shot.
Continuity mistake: As Thunderbird 1 crashes in the desert, Scott is thrown forward and he bangs his chin on TB1's flight controls. But after TB1 has crashed, Scott is shown with his forehead on the controls.
Continuity mistake: When Jeff and Tin-Tin are discussing whether she should go on the mission with Virgil to rescue Scott, the pen on the map on Jeff's desk is facing upwards, but later on in the scene it has moved slightly to the right.
