Revealing mistake: When Gary and Wyatt come home and see Chet turned into a pile of poo, Chet shoots his tongue from his mouth and catches a fly. Look closely, the tongue flies completely out of his mouth and is attached to a metal spring. (01:24:55)
Revealing mistake: When Thunderbird 3 lands in London, the jets do not burn the grass they land on.
Revealing mistake: When Nick is being sucked out of the hole/cave, you can see the wires visible from his waist. (01:20:35)
Revealing mistake: There are two Ewoks Wicket's parent is in search of. One of the those Ewoks is climbing down a mountain and the other has finished climbing down. As this happens, look at the Ewok not climbing. As he bends down, half way down his left leg, there is some sort of fold there. This is mainly due to the fact that the Ewok actors wore costumes whilst filming. The fold is coming from the Ewok costume. (00:07:50)
Revealing mistake: Throughout the movie closeups of Enik's eyes reflect the lights and set around him that aren't part of the movie. During the scene when he's talking to Dr. Marshall about how the crystal controls the sleestack, you can see the white ceiling of the soundstage and lights which instead should be the sky.
Revealing mistake: When Helga is sent flying into her room, the support cable that is attached to her is visible.
Revealing mistake: Near the end of the film when a building is collapsing and people are running to escape the falling debris, several women along with James Coburn are running up some stairs; a block of cement falls and hits actress Gina Golan right in the head. Instead of killing her on the spot, the bolder merely bounces off her head and she continues running up the stairs. (01:40:55)
Revealing mistake: When the tanker crashes at the end the driver is clearly wearing a crash helmet.
Revealing mistake: Some of the shots involving the terrorists firing at the prototype suit are "flipped" duplicates of other shots. In the scene where he first emerges from the cave, several of the terrorists are firing M4-type rifles with the ejection port on the LEFT side of the rifle. In reality, except for a few specially made versions, all M4-types eject spent brass through an ejection port on the right. Later in the scene, this shot is repeated, but with the proper orientation.
Revealing mistake: During the invasion of Dune by the Harkonnen, a Sardukar soldier throws a guard from what appears to be the palace's wall. When he hits the ground all the bodies around him bounce as if they where lying on some sort of cushion. (01:09:50)