The trick that involves Cloudshifting or Unsummoning (or any similar effect) a card with the Oblivion Ring effect (most commonly in current standard is Fiend Hunter) to permanently exile a creature is well-known to even mildly experienced players, and questions related to it are relatively common on forums.
Recently, I've had a player claim that, at the time that a recent GP was played in my hometown, he was told by a judge that this trick will also work on a Fiend Hunter that has been on the battlefield since the beginning of the turn with a creature that is already exiled. This supposedly results into a permanently exiled creature (the originally exiled one) and a second, "temporary" exile.
Since I have never seen anyone claim so or ask the question, I find myself having to ask because, well, let's just say that the "judge aura" is not exactly helping me making my arguments here, and I am much less experienced than the other player. My only theory is that there was some miscommunication and the judge assumed this was the classic, constantly-asked question about a Fiend Hunter cloudshifted as it enters the battlefield.