Six percent of people think they can beat a grizzly bear
The first and only comment on the article linked in OP is probably one of the ones who thinks he would win. He States:
"I would point out that frontiersmen, documented, did kill grizzlies hand to hand - but with a knife inserted in just the right spot to hit the heart. Without a knife you are going to be dinner...and modern men without experience of this sort of thing likely would be digesting in a matter of minutes."
I know I would think that hand to hand kinda precludes you having a knife!!!!