The first one is getting emotional in the first place. His team and Ukraine's intelligence services should have spent weeks interrogating and trying to provoke him in order to desensitize him to this kind of shit. Trump, Vance and Musk are primarily trolls and they should be dealt with as such.
He should not have interrupted Vance answering him either. That was fatal.
He needed to stay calm and slow. He did better than any of us could ever have done, but it wasn't quite enough for this situation. He could have looked a lot stronger and I think we need everything we can possibly get in the situation we're all in right now.
I want to highlight this comment too: https://news.ycombinator.com/item?id=43211604