The world's leading expert in football TBI who devoted his whole life to studying this one issue predicted Tua's second concussion before the Thursday game without examining Tua because he could tell from six seconds of video that Tua had been concussed four days prior.The difference is there isn’t a team of professionals evaluating or making a determination. There’s a person watching for signs of a concussion that unilaterally gets to make a determination to remove a player from the game.
That same person who decided that Teddy Bridgewater needed to leave the game for safety reasons also thought that Braxton Berrios was totally fine.
A team of professionals cleared Tua to play both that Thursday and the prior Sunday after the hit.
"But the docs said that <player X> was ok" is not a defense anymore, hence the NFL deep-diving the protocol right afterwards. That's an acknowledgement on their part that the prior protocol ("docs running field tests in a blue tent") wasn't enough, no?