I don’t believe this study at all. It is considering that bears may run away. To stop a bear with a less than perfect shot takes a high caliber slug. Anything less is either scaring the bear or making him mad. Don’t expect to scare away a mother bear.
The rare brown/grizzly mother bears that charge humans should be shot, and removed from the gene pool.
There are propagating their anti-survival "extra-bold" genetics.
Having shot bears with rifles shotguns and a couple different handgun calibers.
Having hunted bears and lived in bear country for over 50’s years.
It sounds like to me you don’t know crap about bears or shooting and killing them.