The defenseless player part states you can't lead with your the helmet, forearm, elbow or shoulder into the head or neck area of a defenseless player either.
So even though it was obvious that he lead with his shoulder, was it obvious he did not target or initiate contact to the head or neck area?
This is Mike Pereira's take:
FOX Sports Video - FOXSports.com
He basically says, the NCAA believes this is no longer an acceptable play, so fans and players have to deal with it.
His article: Pereira: Alabama beats Georgia, with no help from replay reversal
Well like I said, he led with his shoulder, but he led with his shoulder into the defenders shoulder. He didn't aim at the guys neck or head. So, if Mike wants to say its now illegal he's saying so on a very subjective basis which doesn't follow the rules as stated.