Though it's a gamble. If he suffers another concussion on the field the uproar will be deafening and pressure will be for the NFL to act against Miami as warning aftee warning has been missed.
The big issue with Tua is the scrutiny - having his clear concussion against the Bills ignored, and then fencing in Cincinnati, before going down under a relatively soft hit against the Packers. Experts have come out saying he shouldn't take the field again this year.
They make the call, then they have to prepare themselves to accept the consequences. And so does Tua.