Texas head coach Tom Herman is under fire for allowing Longhorns quarterback Sam Ehlinger to return to the game against Oklahoma this past Saturday after he went down on the sideline with what, at the time, looked like a possible concussion-like head injury.

Ehlinger’s head hit the ground after a tackle from a Sooners player, and while it didn’t look bad on television, it caused him to lie motionless on the sideline for quite a while — at least one minute.

Ehlinger then returned to the game for Texas’ final drive.

A concussion expert is now blasting Herman’s decision to allow Ehlinger back in the game. The expert, Dr. Chris Nowinski, doubts concussion protocol was properly followed, according to a report from Dallas News’ SportsDay.

He sent out this tweet:

The tweet was in response to this video below, which shows the sequence of the play where Ehlinger appeared to be rattled:

Texas lost the game 29-24.

After the game, Ehlinger reportedly said he received a precautionary check for a concussion during the plays he sat out.

“I wasn’t ever confused where I was at all,” he said. “It was a hard hit. My head hit the ground pretty hard. … I told them immediately I could go back in. I felt fine. They just took me into the tent to make sure everything was OK, go through the protocol and send me back out there.”

Ehlinger was cleared to practice Sunday and apparently said he “feels great.”