Nope... because at idle, the throttle is closed... And that thorttle opening is less than 10% of the full valve opening... So there is barely anything coming in through there UNTIL the exhaust valve is closed and it HAS to come in through there....

But I was not even joking with the "Poy" being from air being sucked in through the exhaust: Put your finger in your mouth and pop it out sideways, and what you are doing is creating a part vacuum in your mouth, and the pop you hear when your finger comes out is not the sound of your finger coming out, but the sound of the air rushing in.