In the beginning of the movie, German fighters attack British fighters at an airfield in France. In one scene a German Me 109 comes in low over a Hurricane (a fibreglass mock-up), firing its guns. Nothing happens before the Me 109 has passed by. Then the bullets strike the ground and the Hurricane explodes.

The reason must be that the explosive charges that are used to simulate bullet-strikes are fired too late, and the scene is too expensive to be scrapped, since a fullscale Hurricane mock-up is destroyed.