Sorry, had a hard time expressing this one. Be much easier in a classroom setting. Also, I didn't mention but the same applies for buying on the way up. When I said you would have bot back the 50 shares at $580, you could have done a full reversal and bot 150 shares, leaving you long 100. You would have held thru $600 the 1st time and sold when AAPL was coming back down thru it. (from $622 to $599.99)
My main point is; do not fear weakness. Take advantage of it, as you know the truth.