Guncam footage - why aren't those gunners doing anything?

[*Buzzsaw*]

Salute

The Germans did not employ gun cameras as standard equipment on their aircraft, unlike the British and Americans.

These films were shot for the instruction of new German pilots, not as records to allow kills to be confirmed or not.

So obviously the films which best illustrate a successful method to attack B-17's are the ones which didn't end up on the cutting room floor.