Revealing mistake: In the scene where Bond is trapped in Largo's shark-infested pool, he uses his mini air tank to breathe. In most of the subsequent shots, look closely at the actor's face - it looks a lot more like a stuntman than Sean Connery. (01:20:20)
Revealing mistake: When Leslie is fighting the soldiers, one soldier hits a second soldier with his rifle. The rifle can be seen to bend around the soldier's body and then straighten again. (02:12:10)
Revealing mistake: In the opening sequence when Colonel Ryan's plane has crashed and is on fire, you can see a metal pole supporting a burning aircraft shell, not a real plane.
Revealing mistake: When the tail breaks off of the "German" machine and it careens around the field, you can see the little steerable tail wheel used to control the plane in those scenes. In all other scenes this plane has a tail skid.