The fact is the police were called and legal action was taken. Now that it has been escalated to involve the power of state force, that invites a challenge to the charge based on equal accommodations laws.
Considering the state of the society is such that John Oliver's most recent LWT segment is about neo-nazi entrenchment in the party in power, we can't look at this incident and not see a racism mattar. We have to consider if the response of the other parents to invoke law enforcement would have occurred if the color of the offending family was a few shades lighter.