When Amy and Nancy are sitting on the couch talking and drinking wine, Nancy pours wine into Amy's glass, almost filling it; then the amount of wine in the glass varies between shots.
Amy leaves her fitting appointment then the scene cuts to the church exterior. After a couple seconds the clouds noticeably and abnormally move revealing an editing mistake.
When Gamble is chasing Amy in his car, he makes a sharp turn and almost causes a traffic accident. The sharp turn was obviously done by a stunt double.
When the girl is looking through a keyhole in a woman's bathroom in the cinema, her eye is shown and in it a reflection of man can be seen, obviously a cameraman with the camera filming her.
The movie that the people are watching at the cinema is obviously not really being projected. Instead, it's just played over the screen to simulate the projection like it's often done with television in movies.
When the girl gets out of the car at the beginning and points her light towards the killer, obvious light reflection is seen from the light facing the camera.
When the killer is on the top of Amy's car and just before he is going to fall down, he is visibly wearing something on his face which can't be identified.
In the scene where Nancy plays the record album, there are two close-ups of the album on the turntable. From the first close-up to the second close-up, the speed of the spinning record has increased, although the speed/pitch of the music remains constant.