Just looked at the video of the second "hit" that sent Harvin out of the game. I have seen a lot of grumbling by Seahawks fans claiming it was an illegal hit, that it was targeting, that it was defenseless reciever, etc. But I don't see it. All I see is that he went up for a catch and landed on his head. The defender hits him (which he is allowed to do) making contact with his arm and shoulder in Harvin's back. He was a defenseless reciever, but hitting him in the back with your forearm/shoulder isn't a penalty. The rule says that helmet to helmet contact is a foul even if the contact was initiated below the defenseless player's helmet and then later makes contact with the defenseless player's helmet. It doesn't say the same thing for a defender's arm or shoulder, indicating that subsequent contact is not necessarily a penalty. Do others agree?
Also, does anybody know of a link to the first hit that sent him out initially? People have been calling it a vicious hit as well, but I haven't seen it. I wonder to what extent he was concussed on the first play. Does anybody know how easy/hard it is for a player to fake the concussion protocol so that he can get back on the field?