Look, he says the family he hit are friends, so I'm sure that the one game suspension is the end of it (barring the child having been seriously injured which does not appear to be the case). But when you throw an object into the crowd, he almost certainly had no intent to hit that child, or probably anyone, but he acted recklessly in throwing an object into a dense crowd where you would have had to not care that the effect of your act very well might have been injuring someone. If the District wanted to prosecute the crime, they would have every right to do so and most likely would be able to get a conviction. (And in the case of the lawyer who threw the sandwich in DC, one, that probably was an assault but the jury wouldn't have it for political reasons, and if it wasn't an assault it's because there is no reason to think you could harm someone by throwing a grinder at them, while if you throw a bottle of fluid the risk of harming someone who gets hit by it is much, much greater.)