It’s no laughing matter, getting hit in soft armor with pistol bullets. I’ve seen photos showing ballistic putty behind the kevlar, with a crater about two inches deep and wide. IOW, you might not die, but you are sure going feel like you were shot. A novice like this guy, taking hits in his torso wearing soft armor, was probably going to stop shooting and run away when he knew (and he would know) he was taking effective fire.
So, yeah, it would definitely interrupt the train of thought.