This guy either has giant hairy balls or he shoots very straight while shiting in his pants.
I really like the 7mm Mag round it's very powerful and it's the best for long for distance. (I wouldn't intentionally hunt a bear like that with a 7mm mag, I might shit my pants a little less with a freakin' Barret .50 upon running into this huge of a varment.)
He's also very lucky he had at least that powerful of a round or the bear would have chowed on him too!
I'm sure the survival techniques like laying on the ground and covering your head that they teach about bear attacks on TV is what the poor guy did to get his leg chowed off, too. (That picture is gnarley!)
Just shows to go ya', never go into the wild with out a pea shooter.