Here is one persons take on bear fighting-
http://www.findingwilderness.com/?page_id=112lots there, mostly theorys.
"Don’t play dead, even with non-predatory surprise encounters."
"Dr. Steven Herrero, admits that his recommendation for remaining passive or motionless (playing dead) in the case of non-predatory grizzly bear attacks is based more on “impressions from examining similar incidents and [his] understanding of bear behavior” rather than quantifiable statistical analysis. (See page 18 of the Revised Edition of his book“Bear Attacks: Their Causes and Avoidance,” Revised Edition 2002)"