Great points--I think one would have to want to willfully undo the US/UK relationship in order to truly put it in jeopardy as there are just too many wheels turning for stuff like this to cause a problem. Even so, the author isn't terribly off base here, as much as they may just be trying to drum up a story. I can think of several instances where one government got pissed when a senior official from another government used poor word choice or was quoted out of context. These are just the things you have to deal with when everything you say is on record.