You would think there would be powder burns on the underside of the cap's bill, but there's not. Also, the angle of the bill to the gun when it goes off does not seem the same as the holes that go through it.
Of course he claims the gun just went off on it's own. Is this the new 'tactical' way to holster your gun, without looking at it? I've always 'looked' the gun back into the holster - maybe I'm behind the times.