I'm pretty sure an outside view would say it is LWers rather than domain experts who are more likely to be wrong, even when accounting for the selection-confounding Carl Schulman notes: I don't think many people have prior convictions about decision theory before they study it.

I observe that in some cases this can be both a rational thing believe and simultaneously wrong. (In fact this is the case whenever either a high status belief is incorrect or someone is mistaken about the relevance of a domain of authority to a particular question.)

I've noted it previously, but when the LW consensus are that certain views are not just correct but settled questions (obviously compatibilism re. free will, obviously atheism, obviously one-box, obviously not moral realism etc.), despite the balance of domain experts disagreeing with said consensus, this screams Dunning-Kruger effect.

It does scream that. Indeed, anyone who has literally no other information than that a subculture has a belief along those lines that contradicts an authority that the observer has reason to trust more then Dunning-Kruger is prompted as a likely hypothesis.

Nevertheless: Obviously compatibilism re. free will, obviously atheism, obviously one-box, obviously not moral realism!

The 'outside view' is useful sometimes but it is inherently, by design, about what one would believe if one was ignorant. It is reasoning as though one does not have access to most kinds of evidence but completely confident in beliefs about reference class applicability. In particular in this case it would require being ignorant not merely of lesswrong beliefs but also to be ignorant of philosophophy, philosophy of science and sociology literature too.