See it where? This anecdote sounds more like a jury or a judge making an exception in an extenuating circumstance, than the exercise of an existing law, or precedent.
It is an exception because it is not representative of most assault charges in the US. Getting charged for assault, and then a pat on the wrist, for punching a Nazi is by definition an exceptional event. Rolling Stone, a cultural icon, does not gamble advertiser money on boring, unexceptional events.
https://www.rollingstone.com/culture/culture-news/charlottes...