Interesting story.... I'll bet the REALLY, REALLY BIG GUY could be charged with assault in a court of law. Don't know, just saying.
Not sure which is the most ill advised behavior...shouting the expletives or following the shouter to the square and confronting him.
I'm keeping my headphone on! You can yell at me all you want...I'll smile, wave and continue on my oblivious way, assuming you were telling me to have a nice ##$%#* day ....