I did want to add to this. Any real world Griz advice will say that you do retreat, but you do so in a way that doesn't identify you as prey. You want to keep facing the bear, stay large, and slowly retreat. The key is to show that you are 1) not a threat, and 2) you are not prey either. There is a ton of great information from actual bear experts on the subject, and you are right on with your advice, it is consistent with what they say. I wanted to add that retreating doesn't mean turning and running. It means facing the bear and slowly backing away to signal that you are not a threat to the bear.