All you armchair gun show experts feel free to document on time that anything negative has ever happened because the defensive weapon was NFA.
Are you saying that the only way to know it's a bad idea to eat week-old roadkill is to find a case where someone ate some and the results were documented? (I am NOT saying that using an NFA weapon in self defense is as bad as eating week-old roadkill--just pointing out that it's often possible to accurately determine whether something is good or bad without actually finding a case in point.)
What's the point of having a brain, of being able to use inductive and deductive logic, if the only way to decide if something's good or bad is by actually having someone try it to find out?
Hey Frank, I just built a brand new kind of gun. Why don't you stand in front of it for a test. Don't worry, there's no documented evidence of a gun like this one ever harming anyone so it must be perfectly safe.