So what? I understand their false culture, I wai politely when required or greeting someone. I consider them not so nice as it's well known they will cheat or steal from farang at the drop of a hat. They never fight anyone one on one, they are pack animals, I could go on but there's no point, you need to take those rose colored glasses off and see the real thai people in action.
However, it sounds like the Finnish guy was a whinger and arrogant sort of guy, still doesn't give them the right to attack him.