Factual error: There's a scene when Barbara Stanwyck hides behind an open door to avoid beeing seen by Edward G.Robinson leaving Fred MacMurray`s apartment. To make this possible the apartment door opens outside into the corridor, which is an elegant solution for this situation in the movie. But in the real world no apartment door would open by swinging into the corridor because this would give a visitor standing there a punch on the nose when the resident opens the door.
Continuity mistake: When Fred MacMurray and Barbara Stanwyck are talking to each other over the grocery shelf, she has to stand on tip-toes to see him, and even then the boxes on the shelf cover most of her face. But in the tight shots the boxes are down by her shoulders. She even walks off-screen without coming down off her tip-toes.
Factual error: In the 1944 movie 'Double Indemnity', it is established at the beginning that the story is taking place in 1938. During the confrontation between Fred MacMurray and Barbara Stanwyck at her house near the end of the movie, the poignant strains of 'Tangerine', a song written in 1941, could be heard through an open window.
Continuity mistake: Neff's shirt collar is unbuttoned as he and Keyes talk at his apartment. When their conversation carries into the hallway, his collar is buttoned up. As Neff and Dietrichson go back into Neff's apartment, it's unbuttoned again.
Continuity mistake: When Fred MacMurray goes to confront Barbara Stanwyck and eventually shoots her, both when he enters and leaves he is not wearing an overcoat. Yet somehow by the time he gets to the insurance office, shot and dying, and is recording his confession, his overcoat is on a chair in the office, and he puts it on as he tries to make it out to the elevator.
Visible crew/equipment: At the beginning, Walter is waiting for Mrs Dietrichson in the lounge, and as she is using her lipstick in the mirror you can see the shadow of some equipment sweep upwards (probably the boom mic) on the far left side of the screen. They are the only two people in the room. (00:09:48)
Continuity mistake: In the scene in Norton's office where Keyes says "next time I'll rent a tuxedo", Neff goes out to the outer office first and when he gets there, we see him bend down to a table. But in the next shot, Keyes comes out after him and Neff is not bent down.