Pal, you simply don't know what was in that kid's mind when he did what he did... you can only judge him by his words... his words targeted a specific race, which is racist...
As I said before, he could have chosen to target "fat chicks", or "ugly people", or any of another, non-racial demographics for his "prank", but he didn't... he chose black people, a specific race of people...
That choice made his actions racist... I have no idea if he's a casual racist or a full-blown white supremacist, but he has some level of racism in him...
And because he chose to indulge that racist streak in such a public way, he now faces the legal consequences as provided by the laws of New Jersey...
I just don't see anything outrageous about that...