No idea about his pulse rate, but to pull that off he had to be very mentally calm. Be interesting to hear what he said about it and how he ended up with a 9mm. He's clearly highly experienced with bears and intense hunting situations.I see the sense in that. I suppose as a guide he does what he thinks will work.
How does one put themselves in a position to engage a charging brown bear with a 9mm? That sounds unhealthy.
Edited to add: Just read the story. Damn lucky folks there. That dude is one cool customer. Would be interesting to see what happened to his pulse rate during this episode.
I was "charged" once by a cougar, I think I was probably more in the way of the chosen escape route, but stopped him about 18-24" from me. Happened so fast it was just rote muscle memory. Practice, practice, ...