Continuity mistake: Diamond returns to the all-night cafe and parks with his car pointing toward the door. After he goes in and comes back out, the car is in a completely different position, parked parallel. (00:10:20 - 00:11:30)
Plot hole: Diamond is in a very small town in the middle of rural nowhere, and it's the middle of the night. His car has just been wrecked, driven over a cliff by the bad guy. Yet on the same night, in the cafe at the end, he offers George a ride - for that same night - to New York. (00:25:30)
Visible crew/equipment: When the Highway Patrol car pulls away from the house, the shadows of the film crew (wearing hats), the camera and a light pole are all outlined on its big white doors. (00:16:50)