I think it was the older man's fault at first. He was talking to the phone and the noise was too loud. The youth wanted to stop him so he tapped that guy's shoulders. But the older man then started the whole thing.
This has been talked about on some local(Taiwan) chat boards. I've seen it a couple of times and completely understand the situation. Too much pressure about sums it up. Honestly, I think the best thing the younger guy could have done is wack the Uncle across the mouth when the Uncle starts the f*ck comments. Its all face...and mouth.