I've seen twenty years in multiple places, most recently in Scott Keith's latest book: Wrestling's One Ring Circus
It's not inconceivable. think about it. He went over in early 99, and the ratings wars were still well under way. WCW had made a habit of raiding talent, and Mahon was paranoid (remember, he originally signed Bret Hart to a twenty year deal in 96 as well!) and thus you get long term contracts for a lot of guys (although Mark Henry's has always baffled me). At the time Slow was one of the big names in WCW, and as a younger guy, could be viewed as a big asset in the future.
so it's not that crazy of an idea that he would get signed to such a long term deal by Mahon. plus, you have to remember that Mahon loves the big guys who can't really wrestle.
