So, the second thing Chiarini correctly points to is the absence of a muzzle flash. This is the frame he uses to demonstrate it.
And you don't see it in the frames before or the frames after either. Never mind the ridiculous frame that Backes put up; we should see it here. There is no reason why we don't. It was a Colt Cobra, which makes a huge firey explosion. The absence of the muzzle flash here proves that the other is fake. I'll say it again, Backes: the absence of the muzzle flash here proves that the other is fake.
Note that this puts us 3/4 through Chiarini's video, and so far, he hasn't said anything wacky or laughable yet. The microphone discrepancy and the absence of the muzzle flash are the only things he has covered, and they are both valid points.