When Jimmy is getting ready to propose, in the shot where he pets his dog, you can see in the first shot from in front he is not moving, yet in the next shot he is walking and leaning towards the dog.
When Jimmy is about to be brought back by the Crow, he has an eerie dream about Lily. If you listen carefully, you can hear two women whimpering in the background music/sounds. This particular sound effect is taken from the movie "Van Helsing" from the first scene to feature Dracula in color. (The only previous scene with him was black and white).