The extra padding on the outside of the helmet really does nothing about protecting the brain from hitting the inside of the skull. Sure it may soften the blow just a smidge, but nothing to have any serious effect. The bottom line is, this is a violent, contact sport. Concussions are going to happen and it is a known risk every time a player puts their shoulder pads and helmets on.
It's sad that this has happened to Austin, he has become a really good player. Just looks like the poor kid has been caught in the wrong spot at the wrong time about 3 times this year. The NFL has done a lot to protect the players, but I honestly don't know how much more they could do.