Continuity mistake: When Nat and Claire's doctor boyfriend eat Claire's very well done steaks, the amount of juice in Nat's glass changes from shot to shot. And in the last shot of the scene, when Nat looks at the doctor, his hair is neatly combed to the side, in contrast to the mess it was before. (00:22:55)
Plot hole: When Daniel is in the air with the stolen plane from the Los Alamos air base Nat suddenly appears from behind. However, Nat had no chance to slip into the plane secretely as there was only one stepladder that had been in his mom's full view while she hugged Daniel good-bye. (01:25:30)
Factual error: In the scene where Daniel is taking off with the "borrowed" B-25 (Mitchell), they have two shots switched. It shows him taking off (a beautiful shot), and the very next shot it shows him adding power through the throttles. This should be reversed.