I’ve seen the film. And as a lifetime fan of the sweet science, I can tell you that was no punch. More of a slap. But unfriendly enough. There’s no audio on the film, so you can’t tell if the slap was provoked or not.
The slapper has been identified by the slapee as Marco Rubio campaign aide Rich Beeson. John Yob, on the receiving end of the slap, is a campaign aide to Rand Paul. The incident took place in a Mackinac Island, Michigan saloon before a Republican séance (aka a leadership conference) where scores of political types were gathering. Yob has tried to make a great deal out of not much, calling in the Mackinac Island police and calling on the Rubio campaign to fire Beeson. Outside of Yob, neither campaign has had much to say about the incident.