The thing with Norris is that his head snapped back when his facemask hit the leg of the RB. That's actually a good thing in this kind of scenario. If it had been the top of his head that hit like that, it would be a much scarier situation. You are supposed to tackle with your face facing the target and not the top of your head. If you look at just about every serious spinal injury in football, you will see that these guys were leading with the top of their head, with the crown of their head. That compresses the spine directly down upon itself and that energy has no where to go, so you end up with broken necks and spinal injuries. His head snapping back from a facing position, the energy disperses. Now, it's a serious concussion, no doubt about that and he might not play again, but I think he will.
I took a lot of heat online when I suggested on another board that Ryan Shazier's injury was his own fault because he did the one thing they tell these guys not to do - lead with the crown of your head. Not that I don't sympathize with Shazier and his career ending, but it was 100% his fault. These coaches tell these guys over and over and over not to do this. Your target gets broken ribs and you could end up in a chair
Mike Utley fell in an awkward way onto the top of his head. Reggie Brown was engaging in a tackle when someone fell into him in that position, he wasn't targeting a guy like that.