According to a British Airways pilot on FlyerTalk, the engine issue in question here was a surge on the number two engine, and it was self recovering. This reportedly doesn’t pose a concern for the current flight, but does pose a concern for any subsequent sectors....
Presumably the return flight from Houston to London would have been canceled no matter what, and on top of that, British Airways would have had a more challenging time performing maintenance on the jet, or even getting it back to London.