Obviously hope Tua is ok, but that was just dumb on his part considering his history of concussions.
He already had the 1st down, so there was no need to lower his helmet and go head first into contact. And for what? An extra half yard? Just get down and slide like you are coached to do and move on to the next play.
I think he was trying to play Heroball because his team were behind and he'd already thrown 3 interceptions.