I'd agree that the 17hmr is not a good choice for coyotes in virtually all cases and glad to hear you are getting that 223 by the door instead. Even with good shot placement, there just isn't much energy in the 17hmr for a coyote, especially as you get out to 100+ yards. Thankfully you must be a good shot (and maybe a bit lucky that he didn't run) as more often than not with a non-immediately lethal impact they'll spin for a moment then bolt off into the brush never to be seen again. I've never gone down that small in cartridge on one, but I have shot a few with a 17 Hornet which has about 3 times the energy at 100. The coyotes I got that were 100-150 yards dropped instantly with barely a twitch, but the one I took at 250 yards spun like yours and took a follow up hit to put down. Now I keep it to a minimum of a 204 Ruger or 223 as I want them anchored instantly as much as possible.