Based on the NFL’s definition of “ataxia”, which btw is correct, Tua still wouldn’t have been pulled out of the Bills game. Per NFL, ataxia has to be secondary to a neurological problem, which everyone on the Dolphins denied and said the imbalance was due to a “back problem”.
One thing can definitely learn, based on the response, is that Tua did indeed had a concussion.
I’m not as concerned they didn’t examine his back. That was not their job, which was to determine if he had a concussion or not. Regardless of what was going on with his back, even if there was a positive exam finding, Tua still could’ve been diagnosed with a concussion. That is, I don’t think concussion is a diagnosis of exclusion.