I don't think it's a theory, I it's a fact. Obviously, your analysis is on the money, the only way it could fire twice is if the trigger is pulled twice. The point is, as you stated, an error on the part of the shooter, but still, there is a preponderance of firing twice wth this pistol, doubtlessly due to the recoil. Maybe the shooters need more practice, but it does happen. I fired it, and again, like you said, it isn't for the faint hearted.