Bullet impact with a vest on? It won't knock a man down. Cops get shot with vests on regularly - they don't just fall down and knock themselves out. That was a little weird to me to m too - but I guess it could be worse. It was at least better than the goofy stuff where somebody gets shot and goes flying backwards 3 feet.
That was cold, but also a good hunch. This long into the apocalypse and the hiker can't take down a single zombie? Dead weight...
I thought that was pretty cold too, and I was surprised at how calloused they were that they didn't even talk about it. A friend brought up a good point about encountering a solitary person at this point. It isn't a universal rule, but individuals likely cannot be trusted. The only reason someone would likely be surviving alone is that they can't keep friends, or worse, have malicious intent at this point in the Z.A. Your more trustworthy people are likely to be small groups of people that can function together. That hitchhiker may jump in the car and shoot everybody the second they fail to watch him and then take what he wants.