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. Later, the coat is missing but then is back in another scene.
When Dorothy gets into Larry Fleming's woody wagon, she places her suitcase vertically between her and Fleming. When Sam Hurley gets 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 starts at its peak, which would be impossible for an electric-powered mechanical siren. Essentially a motor with blades attached, it could not start at maximum speed without first winding up to that speed from zero. However, there is no physical siren depicted. The siren sound may be a taped recording transmitted to speakers. A recording could have been created or edited to contain only the peak siren sound, or played back with output suddenly switched on to broadcast sound.
The film is obviously sped up when the station wagon turns off the road into the desert.
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, it should have been impossible for Dr. Garven to drive into the ghost town seemingly unimpeded.
The two guys in the helicopter discuss "Lost Hope City", the old mining town that will be blown up in the bomb test. The passenger confirms it's a "ghost town" saying "We went through it yesterday just to make sure. Maybe we better give it another look, just in case." The helicopter then flies down and hovers a few feet off the ground and then flies away. They must have done a similar cursory inspection "yesterday", as it would have been easily determined that the "ghost town" was occupied simply by walking into Asa's house.
(at around 4 mins) The passenger in the helicopter 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 asks, "What's that?", but the other actor points at the same time - he forgot he wasn't giving the cue this time.
When Kay stops at the gas station, she says to Arthur, "I'm glad you noticed the gas", implying they are low on fuel. When Sam hijacks the car, he doesn't stop to consider why Kay pulled into the station and leaves without adding any fuel.
(at around 3 mins) The announcement over the loud speaker ends with the statement, "The scheduled time for the blast is now zero six hundred in the morning. No military person would add the redundant "in the morning" as, by definition, 0600 is six a.m.
The Control Station Announcer refers to the coming detonation measured by an impossible bearing, "from the central point on a bearing of 10 degrees east of west." Bearings are typically measured from North or South. One could interpret a meaningful direction from a non-standard angle from East, West, or some other compass point, such as 10 degrees north of West or 5 degrees south of Northeast. But a bearing angle measured east of West is meaningless, as would be an angle east of East.