True that.
And he has slipped up. Majorly.
SPOILER
He sent Ser Fatty to give Sansa that necklace, and make sure she was out of there before it kicked off. He then reveals the necklace is a fake he commissioned, before leaving it on Ser Fatty's body. Whoops! Not gonna take long to find that, and then the maker, and from the maker, the commissioner of the work.