In a way they could be considered your coins as you did the mistake, but then again IMO you don't need to give away your own coins because of this. Even though you did a mistake you don't get anything from it if you return the amount you sent to yourself. Would be more fair to just ask it back like you did and well, if some never get's returned then that should be deducted from the pre-mine. Everyone does mistakes and as you are a part of the developer team I would consider this a small mistake and you probably learned your lesson from it.