Other mistake: Marlowe fires several shots at Art Huck and Lash Canino but if you look at the chamber when he takes the gun out from under the dashboard, there are no bullets in it. (01:41:45)
Other mistake: About two-thirds of the way in, Robert Young re-visits the 'scene of the crime'. While climbing up the steep bank from the ravine, he reaches the top and, and in a very short shot (a few seconds), his shadow is cast upon the painted background scenery.
Other mistake: Throughout the movie, Fred MacMurray wears his wedding band, even though it's mentioned several times that he is single.
Other mistake: Detectives Dundy and Polhaus visit Bogart at 3:40 in the middle of the night as we see the time on his alarm clock after they walk in. In the previous shot it's impossible to tell what time it is time because there are no hands on the clock. (00:11:10)
Other mistake: When Farley Granger sneaks out of his flat to go to Robert Walker's house, there is an EXIT sign over the door. Maybe in a theater or cinema, but in a private apartment?
Suggested correction: 1) This only appears in the preview version of the film, not the final version. 2) Why would an apartment building not have an exit sign? Can you cite a reference for this? I would think someone making a contemporary film would notice if it was such an obvious error you think it is.
Other mistake: The first time we see George Loomis back at the Rainbow Cabins after his supposed death he's by the garbage cans in the back of cabin B with a brick wall on the left. The next time we see him two shots later the film has been reversed with the brick wall now being on the right. (00:46:45)
Other mistake: Holmes appears disguised as a Sikh, complete with turban and beard. Although his face is black, his hands are without any make up and are white as snow.
Other mistake: Near the end, Harry Lime is trying to escape through the sewers of Vienna. There is an opening to the street; Harry puts all his fingers through the holes, trying to lift the metal plate, but Harry has a pistol in his right hand; there is no way he can poke all his fingers through with his right hand with the pistol in it.
Other mistake: When the invitation to the Hunt Ball is shown on the screen, it says that the ball is on Thursday, March 7, but on the night of the ball when Lena gets the telegram from Johnnie, the date of the telegram is March 8, 1938, which would have been the next day. And March 8, 1938, was actually a Tuesday and March 7, 1938 (the day of the Thursday Ball), was actually a Monday.