Harry ain't too bright. But he figures it out in the end. Mab protects him and has protected him, more so than Lea. I think that Mab calls out Titania in Battle Ground over this. When she tells Titania to do her duty. Her duty is to protect humanity from Mab, not to sacrifice the Archive for personal vengeance.
I can't figure out how Jim is playing this, but Mab and Titania seem to be two faces of one of the Fates. Mother Summer and Winter one of the others. The Ladies maybe the third. So Mab may be the one that crippled him assuming it wasn't random bad luck.