You made a good coyote out of that one. I have no doubt that you can make that kill. When I was about 15, I was in my front yard shooting my Crosman 2100. A large chow mix had gotten into our fenced in back yard and was attacking one of our cocker spaniels. I tried to run it off but it stood facing me, bared it's teeth at me, and growled at me. I pumped her up to 10 and loaded a Crosman Copperhead pellet (the only kind available at the local Wal Mart back then). I put the front sight right between it's eyes and fired. It turned tail and ran about 50 feet into the wooded lot next door before it dropped dead. Granted I was only about 8 feet from it, but my gun was less powerful than yours, my pellet was a wadcutter, AND the dog was a lot bigger than a coyote. It was a HUGE dog. It's owners let it run loose all the time and got snotty with us when we told them they needed to keep it in their own damned yard.
Well, it never got loose again. They came around about a week later, asking if we'd seen it. They had been out of town on vacation when it happened, and had just let it run loose.
Sucked for them.
These little pellets have a lot more penetration than you'd think.