I do believe this was a genuine wolf hybrid. When I first saw the dog, I said to him that he looked an awful lot like a wolf. I have no reason to doubt him, old dude living on the Navajo Res. FWIW, I googled wolf hybrid and there are a lot of people selling the puppies!
http://www.wolfpark.org/wolfdogs/Poster_section3.html
Check about halfway down the page, under Wolves Without Wolf.
It's actually a really interesting website, if you have the time to check out the rest of it.
susie