Board Thread:False Info and Speculative Discussion/@comment-11584966-20160128152215/@comment-4723271-20170723021534

How long he had been a werewolf at the time is irrelevant. Its still canon since there's nothing to prove otherwise. Not to mention Scott had to have gotten that info from someone, and since the only other werewolf he knew was Derek, its a safe bet he gathered it from a reliable source. Or it could've been Deaton but all that's just speculation.