Yes and yes, and it's a penalty, yes. "Dirty", though? He's running through contact. He pushes McCoy to the ground. His helmet caught McCoy's jaw, but most of the impact was from the neck down. It just looks bad because any impact with the helmet causes a huge whiplash (which is why people use it in the first place).
This is a big hit to me, nothing more. I don't see a guy that should be removed from the league at all here.
I just don't know how you could possibly see this as "running through contact". As I've posted he could have avoided the helmet to helmet entirely if he had just attempted to pull up. He had plenty of time. He chose not to, and should be punished severely for reasons that I've stated multiple times in this thread and you've chosen to ignore.