He had to dispatch the bear quickly with the bear biting Sam even harder as he was stabbed.I think thats why he stabbed the sucker so many times, and didn't stop uintil Bruno did not move,as he has said. When a bear has a mouth full of something and it is stabbed or attacked,it tends to blame it on what it has in its mouth. This I know from men who have had the misfortune to have their forearm in a black bear's mouth, while others beat on it.
Kanawa succeeeded admirably in this and it likely saved Sam's life because Sam's back could have been broken, a bears mouth can deliver a bite which is in the 1000 pounds per sqaure inch range, stronger than a wolf's, (look at the mouth muscles on a bears head.)
Again a great job by a dedicated and loving man.