When the unnamed photographer raises his camera at Jenkins, a human hand can be seen assisting with the puppet's movement from below.
When the picture of the impostor is seen in the newspaper, humorously, the strings are visible.
When Elliot picks up the radio microphone to call Search Control, between shots, his radio head-set (which is on his shoulders), has suddenly turned round. Similarly, when Hale says, "Three to four hours at least,", Elliot has his head-set on his head, but back to front.
As in The Uninvited, Alan does another quick change of clothes aboard Thunderbird 3 before climbing into the lift. Scott also does a quick change; when he arrives aboard Thunderbird 3, he is wearing a yellow suit and orange shirt, but just before blast off, we see him in his usual blue roll-neck sweater, brown trousers and grey checked jacket.