[turner]

I realize it's a little late to mention now, but if you are ever in that situation again I like the shot a bit higher, right at the bottom of a whitetail's white throat patch. That shot when straight on will simply break his neck, ensuring zero tracking required. If he's walking with his head too low for that shot, there's lots of things one can do to make him stop and raise his head; whistle, grunt, etc. Anyway, just a suggestion if the opportunity arises again.

I hope you've recovered your buck! Good Luck!