Even retrospectively, it is unreasonable to expect to practice/train for use of a firearm defensively for a situation where you are firing a rifle at short distance (likely yards) at a moving target (bear) while trying NOT to shoot yet another moving target (person) in close proximity and under extreme stress.
Training for defensive use of firearms can be done in a way that safely simulates some degree of stress. I've done some Three Gun stages with moving shoots and no-shoots in proximity to each other. If I hit one of the no-shoots I'd have to tape it up, lose points, and get razzed by my friends. That's very different from having the consequence of dying, or shooting a friend, to be sure. Without a doubt, competition stress is different from bear-attack stress. But it's way better than nothing.