All well and good but Coyotes don't fight fair - they fight in packs. I have seen as many as 8 take on one dog. Dog dead.
Me bet is that under most circumstances even a pack of coyotes wouldn't got after Bear (at least when he was a bit younger). Sure, if it came down to it, they could kill him, but the cost to them would not be worth it. He's a good bit bigger than your average shepherd.