Of course he did.
I have worked in Thailand for many years and lived here for over 20 years.
Youths just don't do those things without being provoked, yes in other countries not Thailand.
The culture is very different from that of the west, an aggressive blast of a car horn, the middle finger, yelling out like a lunatic is considered provocation, I see this behaviour everyday from foreigners on Soi Buakhou. He's upset them some how.