Yeah, it's not like a cougar/panther attack where with those, if you have decent health, you can survive the initial attack, throw it off you and shoot it in the head as it's charging in for the follow up attack. If a grizzly gets a hold of you, you're done! Too bad there isn't a defense mechanism built in, so that if it gets you, you pull out your knife and stab it or something, giving you time to recover and shoot it albeit at the cost of damaging the pelt.