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: After Manco beats up Cavanaugh and places Cavanaugh's back up against the bar, while Manco faces him, three of Cavanaugh's henchmen appear at the entrance of the bar demanding that Cavanaugh be released. Manco turns around and kills all of them with his pistol, while Cavanaugh falls to the floor crawling toward his gun. Manco is walking toward the entrance of the saloon with his back to Cavanaugh. Manco draws his gun and kills Cavanaugh without looking at him. If you look closely at the tip end of the pistol, you can see that the only thing that Manco would have killed was the saloon floor. (00:17:00)
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: In the scene where a tank is being pushed to the side by another, it's clear the tanks are miniatures.
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.