That's a lie. FB did not aid in anything. Google is not responsible for people who use gmail to plan crimes, nor are ISP's responsible for the content of the packets that go over their wires.
Facebook's algorithms absolutely were responsible: they amplified the propaganda that led to deaths. And their money-first-research-second approach at censorship is part of the reason.
Rather than turning off the service, they let it run wild.
FB is to blame for aiding and abetting.