6. What did they shoot 'em with - a .25 automatic?
I used to make tooling 'n such for ballistic helmets and armor. "Bulletproof" is a very relative thing. Most of the stuff described as bulletproof is nearly transparent to common hunting rifles. Ours were tested with .44 mag (pistol) and soft bullets, and those penetrated most of the layers of Kevlar. IIRC, even the modest M1 Carbine has considerably more wallop than a .44 pistol.