Glitch with Hinterland's quest "Bergrit's Claws"

I also have this problem, I think I know what causes it though it could be just a coincidence but my last bear was at low hp and was killed by those npcs that go stealth and attack you from behind, they also killed one of the dogs that i was fighting around the area and it froze in place as well. Sadly I still haven't gotten my last claw and I searched quite a while without seeing another of those bears.