A father killed a black bear that was going after his son last year, by throwing a small log at it. Crushed its skull, IIRC.
I believe the father got cited for improper storage of trash, but not charged with anything.
Of course, the trash could well have been what attracted the bear in the first place.
But back to the main point - a thrown log stopped a bear. Odds are, the father grappling the bear would not have gone so well for the family. If any weapon is available, it probably beats bare hands.