"Reductio ad absurdum"
My all time favorite was probably the guy who claimed that the second I reached for a holstered gun the (obviously) 97th level ninja master facing me down, Sensi Hoo Flung Poo, I guess, would use his thumb knife to amputate my arm and would then take my gun
My niece teaches Krav Maga
She took my gun away from my holster once;
Damn scary quick.