When Pinson pulls away after spotting the roadblock ahead, there is a dent in the car's left rear fender. Then when he stops just before the roadblock, the dent is gone. After crashing through the roadblock, the dent reappears.
Near the beginning of the film, as "Morris" is unlocking his car, a man in a light-colored shirt just standing there is reflected in the car's window.
After Pinson shoots the uniformed officer suspicious about his fishing story, as he pulls away, a reflection of three heads is visible in the car's driver-side window.
When the cops are staking out the man picking up the machine guns, the edges of the material being used to shade their car to prevent reflections is visible flapping in the breeze.
In the version I saw on television in the late-1970s, Pinson, after being captured, explains to Walsh (via flashback) that he returned to consciousness after having been buried by Bennett and dug himself out of the shallow grave with his hands.