Post what you want in opposition & just ignore him or block him. You don't have to engage him. Correct the record & walk away. Or not. I am introverted but enjoy the interaction on this site where I can not be punched in the nose.

I have a friend, on FB, who copies & posts any old crap her other friends share ... with the expressed expectation that I will correct it for her, if it's BS. On anything & everything!! So, others often see me as a 'fucking know it all'. Not everyone has read her posted comments, acknowledging that she posts, then waits for me to invalidate it, or support it. She also leaves the post up (sometimes with multiple likes & support comments), but with my correction attached. She knows that I hate distributed misinformation more than being judged a bitch.

So, it's up to you @HappyCanuck; is the truth worth your investment? Given the other zoomers will re-share the BS, without your support. We learn who to trust & respect, by their support of the facts, with evidence. I'd raise a new post, not reference the oracle or zoom event, state actual facts with evidence, & tag the other zoomers, but not the oracle. (They may find it's not the first BS accepted; and be grateful to you.)

Instead of leaving everyone in the groups , due to one fruit cake , you may consider blocking him . That way you won't see his posts in any groups , although I don't know how that works on Zoom . Good luck , Hon !

as anywhere you'll find all kinds. rely on your eperiences, knowledge and logic if something appears exagerated or just plain wrong