The mistake is he thinks that religion in general is some kind of scientific area of expertise (in which he is a learned scholar of course) and is a subject to Dunning-Kruger. And hence he can't keep his insights to himself, like a chosen one who is right and everyone else is in the dark. Spiritual pride. Paradoxically, the correct behavior here IS to keep it to yourself, and that is the prime directive which he himself not following through. At least he is forcing objective realism, political mainstream bs and official history.