Continuity mistake: The stains on Mrs. Crawford's top change position between the time when she falls on the floor, seemingly dead, and the time when Nunally and the paramedic rescue her. There's a conspicuous stripe of blood drip when she falls, while she shows just dot-shaped stains in the later scene. (00:10:45 - 00:16:10)
Continuity mistake: When Ted Crawford enters the bedroom where his wife cheated on him, he stares at the bed, which is differently lit between shots - in the first angle, it's sunlit; in the side view, it is fully in the shade. (00:06:40)
Continuity mistake: When Ted Crawford asks for Lt. Rob Nunally on the phone, the conversation is played in continuity, but there's a car in the zoomed-up view that disappears in the view behind Hopkins' shoulder. (00:05:35)
Continuity mistake: When "Mr. and Mrs. Smith" are on the terrace and he asks her to dinner, the lighting of the scene changes dramatically between shots, to the point that you can also see the outline of Embeth Davidtz's fingers behind Billy Burke's neck through the robe in the frontal view, mismatched with the back view, robe collar in full shade and no hand anywhere near. (00:04:35)
Continuity mistake: At the beginning of the movie, Sir Anthony Hopkins' character gets to his sports car and drives off to commit murder. The shadows on the tarmac outside the hangar change in the span of a few seconds. (00:03:50)