yeah, this bear seem like a problem bear. It headed straight to human habitation from the mountains. The first sight of tasty meal was a juicy fat human. there wasn't a deer in nearby.
I think a 6'' inch blade full tang millitary version might be much better than pocket knife. The knife is last resort of course. All literature suggest that human stand better chance of survival if he fights off a black bear. There are plenty of actual incidents where people fought back black bear successfully. However, one shouldn't fight back a grizzly because it will kill a person faster than black bear. By playing dead with grizzly , the victim has better chance of survival than with black bear. Grizzly tends to feed on mostly on salmon, dead carcasses, berries. Grizzly tend to loose interest in victim quickly if he plays dead. One should never run away from grizzly at all. It automatically identify the victim as prey. Black bear doesn't loose interest of its victim. It will continue to feed on it.