Not really a bug I guess, but I was out shooting some Mutant Boars and I think that they come way to close when they attack you. Most of the time I can't see them because I am right in the middle of them and look out of their back ends :) So maybe tweak some numbers a bit so it stays a bit further away.
LOL I guess its the same for mutants. Seem all boars are that way. I remember quite a few rescue missions because of their friendliness and quite a few deaths :)