"I wonder if this incident could have been caused by the argument kindling a vestigal cultural issue of 'face' in the guy."
Could be. Years ago, there were some ugly incidents in the Gulf of Mexico involving Vietnamese working as commercial fishermen. I don't know whether the Coast Guard was ever able to really quell that territorial behavior; it may have subsided because the original refugees quit working the boats and their sons took over.
The problem with the fishermen in the gulf was that Texas fishermen were pissed about two things:
1.Vietnamese ignoring unofficial territorial 'fishing rights' in areas where the Texas guys had staked out claims for years. The newcomers didn't acknowlege any traditional territorial rights.
2. The Texas guys were being outworked and outfished by Vietnamese, whose entire families worked virtually non-stop--and some of them had access to newer, more efficient equipment.
The violence has subsided. I think the Vietnamese won. At least in my area around Kemah, Texas they seem to own most of the boats and wholesale fish markets down by the bay.