I've seen him in a couple different locations, probably trained by someone, though. He was always up when I've been through there, but, again sometimes he's been moved around a bit. I've even actually seen him out in the valley once. I do not believe he has a placeholder, so you would probably have to wait for him to pop if someone has killed him.
Sorry don't know respawn on this guy, but I'm pretty sure he's always up right after a patch (if you want to wait that long). This is a pretty easy step, though, so you could skip it until near the end of the quest if you had to.