Factual error: SAC's airborne command post is shown in several scenes. Problem is, while there is such an aircraft, it is not a KC-135 Stratotanker, which is what is shown.
Revealing mistake: When Denis runs out into the field after the nuclear attack, she brushes up against a dead cow, and the cow moves like a stuffed prop. Real cows are much heavier than that.
Other mistake: When the Soviet attack occurs, farmer Jim Dahlberg carries his blinded son to the farm's shelter. The dust cloud from the nuclear blast in this shot is blowing from right to left, yet the flag in front of the house is blowing into the opposite direction. (00:59:50)
