I’ve met him and seen him speak in person. He’s a phenomenal legal mind and a great presenter.
I am willing to cut him some slack. If I had to speak as often and on camera as he does I am sure I would say some weird things but he does get rather enthusiastic about specific things that strike me as odd.
This is a rather extreme position. Historically, non-flagged combatants were often killed outright. It is a big leap to make the conclusion that he did based on history and accepted international law.