I would say this is a spray success story. My readings on bear attacks is that they are fast, and when hit in vital organs continue with their charge until totally exhausted, then they die. Meaning, yes, you got off two good shots, but will get mauled/killed anyway.
My point is the spray screwed up the bears senses, which drove it off. Yup, the guy got mauled, but he is alive to tell his story.
Personally, a heavy caliber pistol and spray would be a good combo.
We don’t know enough to determine if he used the spray before and or just during the mauling.
With practice, one should only need 1.5 to 3 seconds to deploy a firearm or spray if holstered if one has it in hand more like 3/4 of a second to deploy and get hits.
With most bear attacks one has more then a few seconds to realize what is going on if paying attention.
The key in any defensive situation is to recognize early that one might have to defend oneself. Thus giving you a change to deploy your defensive arms or get ready to.
I have heard over and over from people who have been attack does not matter by what or whom I didn’t realize or think on could happen to me.
Be alert, practice and prepared.
I could go for a gun that sprays and fires rounds at the same time.