From my Study of Case Studies, the Study cited above, two other American Studies, and a perusal of book; "Most" Black Bear Attacks that lead to Deaths are Bears that go Predatory, while "Most" Grizzly Bear Attacks are Accidental, Mother/Cub Related or involved Bears Protecting a Food Source. That does not means that a Grizzly Bear will not go predatory, it just means that it is less likely. In fact the most interesting difference between the Species is that Black Bear Mother will simply drive away a "Threat to its Cub(s)" while a Grizzly Mother will "Kill the Threat"