Nope. He does not need to cool down. He needs people to realize when "trying to help" is not helping. When it's actually about appearing smart or appeasing one's anxieties or showboating or controlling or getting nice points.

If you think somebody might benefit from your advice, you could ask. "Hey, I have been through X, would my opinion be useful?" But before you do that, maybe think about the vast number of people who have already jumped in to offer unsolicited, unhelpful, and unwanted advice. And maybe just trust that if a person needs your advice, they'll ask you for it.