I knew of an Indian woman in Canada who played dead and survived. Her husband told us the story. the bear approached her and slapped her around, she fell to the ground and played dead. the bear buried her with dirt rocks and sticks and then it left. When she was certain it was gone, she got up and ran home. He wounds took years to heal, according to her husband.
From my reading of wildlife books, playing dead only seems to work with Grizzly and Brown Bears as they may see humans as rivals to dominate. Once their opponent is down and submissive or "dead," the Grizzly may feel that they have dominated and move on. No so with Black Bears who don't seem to see it that way at all and will continue an attack even if the person is playing dead.
Big time infections can develop from bear claws.