Considering concussion symptoms aren't always immediate, and he's already had clear concussion symptoms dismissed before, then actually was concussed; yes, I would assume they'd be watching for his head slamming on the turf. His fragile melon in particular. Are you telling me that the observers aren't looking for head contacting the ground? They're only looking for the birdies and stars to spin around above his head like a Bugs Bunny cartoon?