Dr. Chris Nowinski, the CEO of the Concussion Legacy Foundation, ripped the NFL's concussion policy for being a "fraud" when the Colts were allowed to put quarterback Jacoby Brissett back into their game on Sunday after he took a brutal hit to the head. The NFL's chief medical officer Dr. Allen Sills would probably disagree. 

On Tuesday, he told reporters on a league conference call that the Colts and the NFL followed all of their protocols when they allowed Brissett to re-enter the game.

"All of our protocols were followed," Sills said, per ESPN. He also said that Brissett passed three concussion tests -- two during the game and one after. 

Here's the hit in question, along with Nowinski's criticisms:

Brissett was back on the field for the Colts' next possession, even though he needed to be helped to his feet and appeared to be woozy when he walked over to the sideline. After the game, the Colts released a statement saying that they followed the concussion protocol. 

According to Sills, Brissett reported "mild" symptoms 20-30 minutes after the game and was placed in the concussion protocol "out of an abundance of caution." He also pointed out that concussion symptoms can be delayed. 

But that's probably the exact point that Nowinski was trying to make. He seemed to be saying that because the hit was so brutal, Brissett shouldn't have been allowed to re-enter the game even if he passed his concussion tests on the sideline, because as Sills himself noted, concussion symptoms can be delayed.

This isn't the first time the NFL's concussion policy has been criticized. In 2015, then-Rams quarterback Case Keenum appeared to be concussed after a brutal hit, but he was allowed to keep playing. In that same season, Eagles defensive back Malcolm Jenkins admitted that he hid a concussion from the team and kept playing. Just last week, Seahawks quarterback Russell Wilson appeared to bypass a concussion test on the sideline before quickly re-entering the game. The NFL is investigating that incident, which Sills wouldn't comment on. 

According to ESPN, Sills did reveal that roughly 37 percent of concussion evaluations this season (including the preseason) have stemmed from players self-reporting symptoms. Last year, it was 20-22 percent, he said. Earlier this year, Ravens receiver Mike Wallace was cleared to play following a concussion, but still willingly chose to sit out the team's next game. Browns top pick Myles Garrett also self-reported a concussion. 

"I'll play through my foot, my arm, anything that's affecting me below my neck," Garrett said, per the Associated Press. "I can't play around with my brain."

In 2015, a study discovered that 87 out of 91 deceased players had CTE. In July, another study found that 110 of 111 of former NFL players had CTE.