You probably forgot the niceties. People seems to expect that you say hello, hi or the equivalent first.
I think it is like that in many cultures. One culture that I find a bit extreme is the Swahili (language and "culture" in East Africa, mainly Tanzania). Any conversation starts with "how are you" which has to be answered (in a positive way). Then you continue to ask about "How is your day/morning/evening", How is the children etc.
This have to be repeated two or three times with variations before anybody even thinks about starting a proper conversation. It is just a script.
I guess it holds true for a lot of other societies as well - you have to do the smalltalk first.
Besides that, he seems to have behaved quite rude.
_________________
Asperger, diagnosed
PTSD, diagnosed
Turette, diagnosed
Dyscalculia, self diagnosed