I know people have been wondering why no one seemed to pick up on it until landing, noting they wouldn't have crossed water etc.... However if that was me I would have been more in the "I'm going mad and there's no way I'm saying anything" camp than the "British Airways has sent us to the wrong country" camp... even if I had thought something was amiss, can you imagine?! "Excuse me, are you sure we are flying to Germany, looks like Northern England down there" would take some self-confidence in my book.