Depends on the size of the Grizzly bear, really. One of the largest grizzly's in the world was 10'6" when standing on its hind legs and weighed 1200 pounds. It took a 338 caliber shot to the brain, and yet still lived through 5 more shots to the chest before dying. If that thing got anywhere near the predator, his only hope would be a wrist blade shoved through the brain. If he didn't do that, the predator would probably be torn to pieces.
Also, Grizzly's are extremely fast. They can run at 30 mph.
I'll let you guys make up your own decision.