I just watched a fish and wildlife biologist bear training and the behavior of standing on his hind legs and putting his front paws on the tree trunk is defensive posture, which says basically, "I'm not sure you are safe to be around, in which case I'm making myself feel better by demonstrating that if I am chased I can climb this tree to escape".

At the same time I don't think it's valid to second guess the people on the scene. Let's not get sentimental about one dead animal in a world where animals everywhere are declining. Let's not get judgmental about policy or homicide investigations. We don't have all the facts.