I think you have provided the perfect example.
That is NOT the perfect example...
In this example, the Americans were clearly acting in a capacity as soldiers of the enemy forces. (They were on subs that were actively engaged in war on the US.)
The dead Muslim - a vile person, sure - was NOT actively engaged in acts of war that I am aware of.
This was an attempt to “look tough” on terrorism and muddy the waters on what is “allowable” to the President in the use of force.
They denied Al-Awaki(?) his Constitutional rights (he was an American), but oddly enough they wanted Constitutional trials for several terrorists in GITMO - NOT citizens - and granted Constitutional protections to the underwear bomber.