Milady, Janice Rogers Brown was part of that decision.

You may like the result now, but "The international laws of war as a whole have not been implemented domestically by Congress and are therefore not a source of authority for U.S. courts. ..." is a messed-up misstatement of the law here.
In the first place, he wasn't taken 'Domestically,' and in the second, as long as we are talking actual treaties like Geneva/Hague, signed by the Exectutive with the advice and consent of the Senate (As opposed to customary international law), it is a very-settled proposition that they do indeed have the same force and effect in our law as statutory law.
By that token, a clear intention to set them aside or contradict them in a later statute would be a sound legal basis for a domestic action that was contrary to treaty rule, silence or indirect conflict does NOT get you there, though.
The DC Circuit is powerful alright, but it is also second only to the 9th Circuit for screwing the pooch in its decisions through a certain willingness to indulge in politically-based decision-making instead of sticking to purely sound legal analysis.