I Have No Idea How The Hell Tua Is Back In This Game After Barely Being Able To Walk

Why am I confused by this? Because this is what Tua did the last time he was on the field: 

Dude took a hit and smashed his head against the turf

I need a full breakdown on what the hell is a concussion? I've had one. It's not fun. I'm for sure not going back to playing football after a few minutes. Sure, I'm not an NFL quarterback but they have 'rules' and 'guidelines.' I was just a dumb kid with a concussion. Not even just that stuff, I have no idea how Tua is able to play from a physical standpoint. 

I'm all for gutting it out and playing through injury, but if someone can barely walk, maybe don't let them play the most important position in sports for a few plays.