You couldn't possibly know if his reaction is appropriate

Specifically when non athletes try and critique an actual player's toughness, they come across as haters more often than not
Well I did think that LeBron looked like he was trying a bit too hard for the cameras, with that collapse and than gritting his teeth while walking off the floor.
That doesn't take away from his performance and the fact that he tweaked his ankle in OT, stayed in the game, hit that huge 3. Has lead this teams sans it's 2 other big stars, pretty much to the finals at this point.. etc etc etc
I'm just saying the whole, "you don't have the stamina to play an NBA playoff game so you cant say shyt" argument is
EDIT:
I'm not saying that I can't be wrong. Maybe he did really collapse in exhaustion and gritting his teeth from the pain. I'm just saying that it SEEMED like he was doing it a little bit for a Nike commercial spot