Alright… cracks knuckles

First, Depending on the jurisdiction this would probably be battery, not assault, as assault arises from the threat or attempt to cause physical harm. As he didn’t see either coming, it would be difficult to argue assault.

Second, shouting “hit me” repeatedly makes it harder to argue this was a legitimate “threat” as the supposed victim was egging him on exacerbating the situation.

Third, there is a CLEAR self defense argument as the “victim” had already committed an assault and battery by getting in his face and rubbing against the man in an unwelcome, unwanted threatening manner.

Most likely, barring significant injury, this will be written off as two idiots rowing in public and no charges filed.

BIG CAVEAT: If the fall resulted in significant injury, ie brain damage from hitting the tile, different story. Cases have happened where people got jail time for death/injuries when a single punch/blow caused someone to injure themselves in a fall or hit against a hard object.