Two bears were killed by troopers so that's definitely possible. As far as how to handle bear encounters, never run. This makes them think you are prey. They have very poor eyesight and are therefore more likely to chase something that runs. If you come across one, wave your hands and shout and basically act bigger than you are.
Looks like they are making a documentary of this guys life/work. http://www.apple.com/trailers/lions_gate/grizzly_man/medium.html
Like the article said, I don't believe the guy didn't realize they weren't dangerous. I think he just thought he knew enough about bears not to be killed by one or was just willing to risk it. I mean, the guy had fantasies about being eaten for goodness' sake. When I picture this guy, I have a mental of image of the crocodile hunter, someone just a little too foolhardy and obsessed, but not oblivious to the dangers.
I saw him on the discovery channel. It was pretty cool. He'd take people to watch the bears go fishing. There would be like 10-12 bears out there. I would have gone on his hike if I knew how to contact him. Peace out. Bear Witch project.
Kind of ironic this thread was re-posted today. This afternoon we had a bear mauling just south of Anchorage. A 15 year old Boy Scout up from Texas with his troop was running on a hiking trail--really, really bad idea up here when you're in the wilderness, but I doubt the kid knew any better. He rounded a corner and sure enough, scared up a mature grizzly. His backpack probably saved his life. Currently recovering in an Anchorage hospital from multiple puncture wounds.
When I was in Alaska, I was fascinated by the book "Alaska Bear Tales". I'll get into it later, but it was a fascinating read. Fascinating.