The NFLPA has reason to lie about its own players?
And sure if he were your child, you'd be upset. But Josh, and Tua, and any other player, is a grown adult and is responsible for his actions. If Tua wants to continue playing despite his 3rd concussion in less than 2 years, with 2 of them so severe he was posturing, that's his decision.
Tua didn't get checked for a concussion in the Bills game. That's why the NFL and NFLPA said he wasn't properly evaluated for one and why the protocol was changed.
And as those posters who were at the game said, he was moving his legs, which can't be seen in that video clip. The Bills' trainers and players were there and ostensibly talking to him. Again the Bills care about the safety of their players and the NFLPA has no reason to lie to help the Bills/NFL out.