Continuity mistake: The wire attached to the roof of the Bodega Bay School that the birds sit on as Mitch and Melanie watch was not there earlier in the movie. We see this left corner of the building up close twice earlier in the movie. The first is when Melanie drives up to Annie's and the second even better shot is when Annie stands by her mailbox as Melanie leaves. (01:29:35)????
Continuity mistake: Melanie closes the door of the phone booth with her right hand pushed up against the window, and in the next shot her right hand is tucked up close to her body touching the center of the phone booth door. While inside, Melanie goes from leaning against the door to leaning against the opposite window between shots. (01:26:25)????
Continuity mistake: The position of Melanie's car has changed from when she first parked it in front of Annie's house. At first the rear wheels are adjacent to the steps, but later they've been moved back slightly so the front seat is adjacent to the steps for Annie to lean in when they speak. (00:18:10)????