So, I had to look this up. Few things I didn't realize. I had assumed that the unaffiliated neurologic consultant on the sidelines had "veto power" over return to play, but that is apparently not the case.
"the responsibility for the diagnosis of concussion and the decision to return a player to a game remains exclusively within the professional judgment of the Head Team Physician or his/her physician designee responsible for the diagnosis and treatment of concussion."
Also, "gross motor instability" is supposed to be a "no go" symptom for return to play. It seems a bit of a stretch that the team physician was able to definitively rule out a concussion as the cause, but maybe he/she was. When this happened to Mahomes in Jan 21 against the browns, he was removed despite not clearly having a concussion due to this "no go" symptom trigger.
The requirements for documentation here are heavy. This should be a short investigation.