The prompt did not include the fact that Trump declared them to be terrorists which I believe is what makes that kind of attack legal. If they are enemy combatants you are allowed to follow up and ensure they have been killed
Not true. Launching an attack on shipwrecked enemy is a blatant violation of the Geneva conventions. [1, Chapter II Article 12] It's also prohibited by DoD's own guidelines. [2, page 1071, section 17.14]
It's not a question of whether or not what happened was illegal, it's a textbook example of a war crime. It's a matter of whether or not the justice system still has enough power to identify who is responsible and hold them accountable.
[1] https://ihl-databases.icrc.org/assets/treaties/370-GC-II-EN....
[2] https://media.defense.gov/2023/Jul/31/2003271432/-1/-1/0/DOD...