Look, "It's true" isn't actually an automatic shield in a debate. Every point a person makes in a political discussion has an agenda - if you're not willing to take the time to explain what your agenda is, people will surmise it from the things you do say. Why you say what you say is often as important as what you say.
If I call a man a nigger, it doesn't actually matter that he's black. I'm still probably being a dick, and I should have a better explanation than "Well, it's true."
I stayed out of the thread after reading the OP, because I knew exactly where it was going. I don't know whose first language is what, but at least for native speakers it doesn't take a genius to figure out from tone and context what that post was trying to do. If facts were all he were trying to talk about, he could have supplied every fact in that post within a paragraph in another thread - starting a new thread, wording it as correction to the reader, and an aggressive one at that, and providing a short, cherry-picked list of facts specifically opposing a particular agenda, all smack of inciting a fight.
But, as I was saying, I stayed out of the thread, and I don't care to read it now because I honestly can't imagine how it would improve my life. And that's a big question I ask myself these days. The point for this post is, dude was being an ass from the get-go, whatever his opinion happened to be on the matter at hand. Maybe he deserved a warning, or a mute. Maybe other participants deserved punishment. I'm not actually prepared to speculate on the justice of the outcome when I have so little knowledge of the subject. But he was far from innocent in the whole thing.