Plot hole: Even if the white blood cells will attack and destroy the sub and the body of Doctor Martin the atoms would still remain and take normal size after the critical 1 hour is up. This would also apply to the laser gun which they forgot or left behind on purpose, as well as several dozen litres of saline solution which were miniaturised and pumped into Benes' body. He's in a lot of trouble.
Visible crew/equipment: In the scene where Jeremy Kemp and George Peppard are playing daredevil in their planes and Kemp's plane hits a brick tower there is a shot of the plane plummeting to the ground. The alert viewer can see the shiny metal wires that were used to support and guide the plane on its way to the ground.
Visible crew/equipment: When Paul Newman takes Julie Andrews up a small hill to explain that he is not going to work for East Germany you can see a shot from a distance. It is clear that this scene was done in a studio, as you can see several lights above the blue background (which is supposed to be the blue sky).
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)Mark Pitta 1
Continuity mistake: When Peter O'Toole is locked in the closet at the museum, he puts a rope through the keyhole and uses a hook to pull it under the door. In the first shot, from outside the closet, the end of the rope is to the right. In the next shot, from inside the closet, the end of the rope slides under the door to the left. (01:22:30)
Factual error: In the scene near the end of the film where Victor Buono is sitting in his chamber addressing his two captives, he opens a can labeled egg foo young with a can opener. He pours the liquid contents into a bowl. Egg foo young is an omelet and could not have passed through the small holes made with a can opener.
Continuity mistake: The cars change shape frequently during the movie. That depends on the fact that many scenes were filmed at real races, with real F-1 cars. The cars that the actors drove were, for the most part, disguised F-3 racers. There are at least three fake Ferraris, and they all look different. One of them seems to have been built to resemble a 1965 F-1, but altered to look like a 1966 model. The non-existent Yamura (built to resemble a Maclaren), that James Garner drives is actually two cars with different chassis, one of them seems to be used very little, except when it catches fire in a scene.