The woodie station wagon driven by Sam Hurley has a desert water bag on the front bumper. The bag is missing in the exterior shot of the car just after Larry Fleming informs Hurley about the atom bomb test. In the next shot the bag is back on the bumper.
Hurley and his accomplices get in the car driven by Kay Garven and her fur coat is laid over the seat back. In an ensuing scene, the coat is missing and then is back in another scene.
Hurley tells Garven his wife is driving a Chrysler. But the shot of car front shows it clearly to be a Cadillac, with distinctive V shaped symbol.
When Jan Sterling (Dorothy) got into Larry Flemings woody wagon she placed her suitcase vertically between her and Fleming. When Sam Hurley got behind the wheel forcing Fleming to ride in the middle between Hurley and Dorothy the three of them are shoulder to shoulder. The suitcase has disappeared.
The five minute warning siren immediately started at peak, which is impossible because electromechanical sirens are essentially motors with blades attached, and no electric motor ever conceived of can start at maximum speed without first winding up to that speed from zero.
Obvious use of models when Sam is turning the car around at the bomb site.
Considering the level of security around the test site, including the number of roadblocks set up to keep people away, how did Dr. Garven manage to drive into the ghost town seemingly unimpeded.
In the helicopter scene near the start, the passenger points at the atomic bomb tower and explains to the pilot that, "it'll be atoms itself this time tomorrow!" In the next shot the pilot points and says, "What's that?", but the other actor points at the same time - he forgot he wasn't giving the cue this time.