Revealing mistake: Just before Anthony Dawson is going to be stabbed to death by Grace Kelly with a pair of scissors, you can see for a very short moment that the scissors are already attached to his back.
Dial M for Murder (1954)
1 revealing mistake
Directed by: Alfred Hitchcock
Starring: Ray Milland, Grace Kelly, Robert Cummings, John Williams
Revealing mistake: Just before Anthony Dawson is going to be stabbed to death by Grace Kelly with a pair of scissors, you can see for a very short moment that the scissors are already attached to his back.
Margot Mary Wendice: How long have you known this?
Chief Insp. Hubbard: Did you suspect it yourself?
Margot Mary Wendice: No, never. And yet... What's the matter with me, Mark? I don't seem able to feel anything.
Trivia: Alfred Hitchcock wanted the film to look as natural as possible, with the camera at eye level with the actors. Since movie cameras were large (especially 3D cameras), Hitch had a small trench built into the soundstage floor, so that the camera lens was, roughly, at eye level.