Continuity mistake: Walter takes part in a trial performance to join Erika's piano master class. When he opens the door to the concert hall his collar button is open, but when the camera angle changes and the door is seen from inside the shirt is closed.
Other mistake: When Erika peeps at a couple at the drive-in cinema, the man makes eye contact, jumps out of the car, and starts running after her. We see her running away, but the guy never catches her, although she isn't running very fast and didn't have much of a head start.
Continuity mistake: In the beginning there is a shootout when the main characters are sitting in a car. The windows of the car are broken at that time. But the next day they are driving in the same car and it has not got a scratch.
Continuity mistake: While Walter plays in the trial performance to join Erika's class she is seen folding her hands in her lap. In the next, close shot (continuity proven by the music) her right arm is behind the back of her chair.