The story I read said the first guy was jumped by a bear after startling it. Probably no time to pull out a holstered gun unlock the safety and shoot it accurately. Combat trained experts maybe but a regular guy unlikely, no matter how many movies he'd watched.

If the buddy had a gun its unlikely that he would be able to get off an accurate shot at the bear only.

But laying down a fog of bear spray is non-lethal to man & bear and skill level is minimal, at least for those of us with wasp-fighting backgrounds.