Like pepper spray, I would imagine bear spray, is just as effective in a good swirling wind, around buildings, or trees and rocks. My point is, if everyone gets a good dose, no one will have to witness the carnage.
On the other hand. If one is in the wilderness, and a bear attacks, and said bear ends up deceased? What compels the "agresse" to notify anyone, knowing the governments propensity to take the bears side, and testify on behalf of a bear, they neither knew, or saw in the circumstances described act? The three monkeys come to mind here.