Revealing mistake: Bond escapes from the buried pipeline when two technicians open a hatch from the outside. One tech unlocks the hatch by rotating a large wheel, which drives the locking mechanism. But when he finally opens the hatch, there's absolutely no mechanism attached. There's just a bare axle that the wheel turns on.
Revealing mistake: After Lansbury makes her clothes start to move, her nightgown attacks someone and you can notice the strings that make the gown move.
Revealing mistake: In the slow motion crash of Steve McQueen's Porsche 917 you can clearly see that the car is empty.