I see it a little differently BouncingCheese. Miller is only open AFTER the ball is in the air. He's actually double covered by the Safety and Corner until Big Ben launches the duck up into the air. Nonetheless, when you blitz, you put more pressure on your secondary to cover in man to man. Its definitely a risk/reward situation. If you're going to blitz and get tricky with the DLine, there are going to be certain times when the blitz fails and you give up a play.