Continuity mistake: When Alan contacts his father at Tracy Island, Jeff asks him "How's the situation, boy?" Alan informs him that Grandma has passed out in the heat and Alan's face is covered in sweat. But after a quick cut to Jeff saying "Passed out?" we return to Alan, and the sweat on his face has disappeared.
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.
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 Kalp makes his surprise appearance via Lopez's secret waterway, after shooting Scott's gun out of his hand, he holds up a test tube of Theramine. As he says, "Remarkable discovery." in the close-up, the position of Kalp's hand differs. (00:34:10)