Team America World Police
If the US or anyone with US citizenship might possibly be affected or for any other reason, they'll step in and claim whatever crap they feel like. Why do you even ask? After gitmo nobody needs to worry about legalities. They clearly don't matter if whichever of the many, many USA TLAgencies gets a bug up its ass.
He's lucky though. He isn't silently being "extraordinarily rendered" for some good old medieval interrogation practice somewhere well outside USoA borders. A public trial show means he'll live.