He was not wearing a "bullet proof" vest. Reports are he bought the vest a knife and some other stuff for 300 bucks. I'm thinking it was just a tactical vest that provided very little if any protection from bullets.
Unless he had a real vest underneath.
Gas mask is not going to stop squat neither was a lot of the stuff he was wearing. Sounds like the media is blowing this way out of water and he was not that hard of a target. Looks can be deceiving.