Sorry to nitpick, but the Guardian US, a subsidiary american company broke the story, and the reporter is an American citizen. Nothing really foreign there.
This is like saying that if Google China does something Google US has nothing to do with it, which clearly isn't the case.
If the Guardian US were independent of the Scott Trust then you'd have a point but as it is the Guardian is solidly UK based no matter where the subsidiaries reside. I'd imagine a story this big would be passed by the editorial board.
For the Guardian US that is Janine Gibson and Stuart Millar, both have previously been part of the UK portion of the Guardian.