I am not sure if this is the first one that took away the sack. One that play it seemed like I saw a head slap early in the contact but I didn't see the prolonged contact required.
What we mere mortals don't know is whether or not the NFL has told the team and players that grabbing the shoulder pads near the neck region is considered to be a violation as well.
The NFL has some funky rules that make us ask, "When is a catch a 'catch' "? This could be similar.