Exactly how you handle these situations. Instead of responding in the same combative manner and escalating things, simply whip the phone out and hit record. Let these a$$holes air themselves out, and then simply post it for the world to see. Too often you see it escalate into a situation where the words turn into the one being discriminated against resorting to a violent response, which turns the a$$hole into the victim and brings along charges. Do exactly what this guy did, and let things sort themselves out in the court of public opinion