I think the young guy was more stunned than afraid. The older guy was basically humiliating him in public by raising his voice at first and followed by his tirade. I'm just curious that if the young guy were to slap him (not sure if he's capable of beating up the older guy since he looked and sounded timid), will he be legally charged? In my line of work, I've handled stressful, angry, and profanity-laced customers through telephone. But in this case I'm not sure if I can speak coherently or give any high EQ response to get out of the spot.
Chinese respect old people (seniors). When the older folks talk, the younger ones listen, just like what happened in the video.