He has every right to claim something and I don't see why he would not until someone tells him otherwise. No one "deserves" to be called an idiot. Ask anyone and I bet they'd say that wasn't called for. I'm done with this pointless bickering, it's going to get nowhere. Have a nice day.
He can comment wherever he wants. You are no pinnacle of wisdom either. You don't insult people when they're wrong. You tell them that they're wrong and why they're wrong. Nothing calls for insulting someone.