Revealing mistake: After Wallace kills the Scottish noble in bed, he jumps out of the castle window into a river on a horse. As he is falling, you can see that the horse is a model and when they fall into the water one can see the fake horse bobbing around. (02:15:45)
Revealing mistake: When Chris Tucker is found dead from an apparent heroin overdose, you can see him still breathing on the chair.
Revealing mistake: After Richard has accepted that he will be king, he appears before a large assembly. Several of the soldiers standing by the walls are obviously plastic dummies. They have unnaturally smooth and blank facial features, and when you can see their hands, they are not grasping their guns, but merely holding their hands stiffly out with the gun between them.
Revealing mistake: When Sara and Ms. Minchin are fighting in the attic, it is night time, but there is light coming through the cracks of the attic.
Revealing mistake: At the start of the film, Sergeant Gunn and another member of his tank crew take shelter in a shell hole as they are returning with fuel and spare parts. Watch the supposedly dead soldier hanging over the edge as they leap into it - he visibly reacts and moves his head.