I have a hard time believing anyone with a capable firearm in hand who is in a stare-down with a big grizzly exhibiting aggressive behavior wouldn't have their finger on the trigger ready to start shooting as soon as the bear began to close distance. It wasn't clear from the guy's article if he would give a grizzly a chance to rethink the decision and run off into the woods, but as was stated above, there's some line in the sand somewhere and it seems open to debate. Hopefully I never have to find out where it is for myself.
On that note, however, I'm reconsidering my bear gun options as I am at a point in my life where I'm going to hopefully be doing more hunting (and potentially with some friends in MT). I have a Glock 31 right now (.357 SIG) which holds 15 rounds. In a stress/defense situation, I'm wondering if it wouldn't be better to have more than twice as many chances to hit something important with a FMJ .357 SIG round as opposed to a .44, .454, etc. I guess the easy answer is "Glock 20" with the same 15 round mags. But same question there... 15 x 10mm rounds vs 5-6x .44 or .454 rounds?
I think I'd feel much more comfortable with the Glock 20 and FMJs (or alternate FMJ and JHP in the clip), but you don't know what you don't know!