I'm in the camp that doesn't think the kid was being racist - I just wish the parents would've been there to help the kid understand that he looks like a goofball. Just like I'd hope you didn't let your kid wear underwear on his head to play in a football game.Because he's a kid and likely has no clue what the heck he's doing. Kids are silly that way. My son put his underwear on his head. That's not how underwear works either.
Now, if it turns out this kid's parents are racist twats (and it's provable), then I'll retract my opinion. Until then, look like a kid being a kid.