I am assuming you did not hit the coyote and you never recovered a corpse? (your post isnt clear) This being the case I would suggest your lead wasp may have gone over him. I read somewhere that even tho you have a tail wind or a head wind the bullet may not drift off to the left or right but may drift up or down :o
Probably stating the obvious but was your settings on the scope correct?
Wind can do the most amazing things in the field and at home (Just ask my missus