That is the letter of the rule but it is usually only called when the DB drops the crown of his helmet, not when the WR drops his helmet and hits the DB in the chinstrap. Sorry.
I agree. I think the only reason as to why it was thrown was because the kid got freaking smoked.
If you look at the rule, Slaughter did not attempt to aviod the head to head. He drove though the kid, striking the U$C's kid with the facemask/crown of his helment. By the letter of the rule, it was a penalty. Do I think it should have been called? No.
Just like I hate holding calls as I played on the line in college, I will give more lee-way as to refs in the secondary. But to me, as a fan and a coach, that should not have been called. It was a knee-jerk OH MY GOD flag.