Well, even if he regains his sanity... his bloodline has become so pure werewolf blood that it's completely impossible for anyone to believe he was ever human.
The effect of the necklace is to purify the blood to avoid being turned into a werewolf. But it seems to have had the opposite effect now. All the blood in his body has been reversely purified. Now his bloodline is purer than anyone else infected by the werewolf virus... He has become a pure-blooded werewolf.