Please explain how the rules account for Kiwanuka thinking Young had thrown the ball when he hadn't.
If Young threw the ball and kiwiwhatever planted Young into the ground on that play, there would have been a flag thrown. GUARANTEED. I said 'rules' but you should be able to comprehend that I meant the new 'way it is'.

Young had the ball.
Kiwanuka f'd up.
It had nothing to do with the refs.
IF Young had thrown the ball - Kiwanuka shouldn't be driving him into the ground anyway.
IF Young had the ball - Kiwanuka could've knocked the crap out of him.
Young HAD THE BALL.
Nobody has successfully explained why what Kiwanuka thought the refs would do is relevant at all in this situation when you KNOW that Kiwanuka was thinking about a situation that did not exist.
Kiwanuka's mental error occurs at Point A.
Kiwanuka then makes a decision based on the roughing rules at Point B.
Point A is what makes the whole thing possible. If Kiwanuka knows where the balls is, he never gets to Point B.