It´s always easier to be wise in the hindsight. In addition to what the others stated there´s one point that really stood out to me. It may sound a bit harsh but I don´t intend to offend you or pass moral judgement. You borrowed a gun and had a vague idea of using it in the case of a bear encounter. By not thinking more thoroughly about it you conditioned yourself to careless fire in the case of a panic. And you conditoned the whole party to assume that unidentified contacts would be bears. That kind of conditioning is much too powerfull to neglect it. It would be much better to set up a plan and brief the whole party about it. This would increase the probability of proper reactions and it might even decrease the probality of a panic.
Thanks for sharing this experience and giving an oppor
tunity to learn.