When the bomb goes off while Paul and Patty are walking down the street, the people in the background don't duck and cover at the same time.
The man on the tractor makes no attempt to shut off the tractor before jumping down from it and landing right in front of the rear wheel, yet the tractor is at a complete stop when he hits the ground.
During a drill in a classroom, the narrator says to cover very tightly the back of your neck. But the little girl covers the back of her head to the top of her head.