I'm confused by this writer. Unless bouncing someone's head off a sidewalk is a new game, it will definitely cause great bodily harm.
That Trayvon was bouncing George’s head off the ground is not at present a fact as determined by a court.
It is the defendant’s story of what happened. And it may be supported by witnesses.
It may very well also be the truth. But in other cases I’ve noticed around here a certain shall we say resistance to assuming everything the defendant says is the whole truth.