Ooh, that's a bit harsh. I too think he's wrong, but no one is perfect. He's clearly a decent enough chap and a pleasant member of our little community, so it must surely be possible to disagree without getting silly over it?
Annoyingly I reported the ableist slur he used against me so it got deleted. I should have let it stand so there would be a record of it. That was when he was trying to explain, badly, something that was well within my area of expertise, by a simple Google search and copy-pasting, out of context, the first thing that came up.
He's also arrogant enough to make sure that everybody knows the price of his very expensive bike, refuses to acknowledge any mistakes he may have made, is giving potentially dangerous technical advice and potentially dangerous advice on roadcraft. I think he claims to be a ride leader or something so surely should be held to fairly high standards.
You mention community and if you want to call it that then this is how it works. When we see somebody acting in a way that is unpleasant and prejudiced, we need to call it out. When we see somebody giving potentially dangerous advice we need to correct it. When we see arrogance and hubris we need to express our disapproval and demonstrate that this is not what we want our community to be.
Now of course I'm not perfect myself, I make mistakes, I'm sure I've been arrogant and unpleasant in the past. I try to stay in my lane and only comment on things I know about, or caveat my comments by stating that it's only my opinion, but when I see advice given that I believe is wrong, and dangerous, and presented in such an arrogant fashion, I am going to call it out.