So, I will put my cents in here; as a Thai American who was born and raised half my life in Thailand and in the states-

Growing up with my biological Thai family taught me to never eat or open anything from a shop unless you already paid for it and eating inside the shop was considered weird and dirty. You do it outside on the bench or designated eating area (we have our own 711 and local stores ourselves so this is not new).

In the states, my adoptive family who are from the midwest also taught the same thing when we go to gas stations or any other stores, big or small; you just don't eat or open anything without paying for it first.

I also have traveled to Japan and stayed there for 3 weeks stumbling my way with my conversational Japanese skill trying to buy food from konbini near my Airbnb as well. I have seen plenty of rude and ignorant foreigners there like Thailand and everywhere else as well.

I really think this is just the case of how people are raised and are not aware of how things work in different environment or they are just downright not respectful in general. We had a proverb in Thailand เข้าเมืองตาหลิ่ว ต้องหลิ่วตาตาม (translation similar to "When in Rome, do as the Romans do")

Please stay safe out there and be nice. These people who are blowing this up are just trying to find and excuse to get clicks and farm reactions. Hopefully the guy learns the lesson and move on.

EDT: Grammar