I don't think he hired Fury, but I'd have to watch the movie to make sure. I seem to recall Fury asking him to take the job he has now, not vice versa. Yeah, there was the pistol scene where he trained him how to shoot, but Garrett also mentioned Ward's shooting talent in the prison-break scene. Anyway, I think the scene was deliberately ambiguous. If Ward had the rifle, it wouldn't have been ambiguous. Likewise, if they had shown Garrett with the gun, it would have been the same. While I tend to think that's the better explanation, I also think it was a bit ambiguous. After all, he could have waited them out if he couldn't kill them then.