The old guy reminded me of another New York moment when Don Zimmer rushed at Pedro Martinez like a mad bull; like Zimmer, he got caught up in the emotion of the moment and forgot he was — well, old.
Having said that, the father-daughter were fully within their rights to object vehemently to having to suffer through the young guy’s foul-mouth. Their ticket gave then the expectation to enjoy the tennis match without the kid’s aggressively foul mouth violating their space.
Once the daughter stood up to confront him, and kid turned his foul mouth directly against her rather than (presumably) the tennis match, then his behavior mover closer to civil assault — because there was some menacing arm-waving / gesturing going on as well. Civil assault only requires the THREAT to injure, not a punch (which is battery).
Once the kid sat down and continued to curse her, its a factual question as to whether she was still threatened - if yes, then she had a right to self-defense, and if so, then her dad would have had a right to act as well (using her right). So in sum — it’s not always strictly a matter of who throws the first punch — self defense can turn on how imminent is the illegal threat.
Now, having a legal right to self-defense doesn’t mean that its the smartest option, especially when there are security guards around. On the other hand, they seemed awfully slow to respond to the situation.
So — the specific facts about what was said, when, will dictate the outcome, and clearly there were a LOT of witnesses who can testify. My prediction is that Dad and daughter walk, the kid gets some sort of disturbing-the-peace charge, with big fine and community service.