And apparently, one of their FOUNDING BELIEFS, is that I had sex with somebody underage (mutually desired sex, according to the Zizians)... and then MIRI, a nonprofit I started, paid money (to a third-party extorter) to hush that up... which payment, according to the Zizians, is in violation of DECISION THEORY... and, therefore, for THAT EXACT REASON (like specifically the decision theory part), everything believed by those normie rationalists who once befriended them is IRRETRIEVABLY TAINTED... and therefore, the whole world is a lie and dishonest... and from this and OTHER PREMISES they recruit people to join their cult.
Yudkowsky is the first person I have ever seen describe this as a load-bearing belief of the Zizians. Offhand, I don't recall the news stories about the murders even mentioning it.
It's in the quote tweets.