Thinking: On Ignorance and cultural acceptance

I'm in Korea; I have been in here for a year. I will be in Korea for a longer amount of time for graduate school. The things I encounter in Korea are things I have never encountered before in my life, and while I was sitting on the bus today I could think clearly about what it means to be ignorant about different cultures and accepting different cultures. I started thinking about this because a few days ago I got onto the bus with another foreigner, who I assume is also a teacher. Everything was fine until I got up to get off the bus, and the lady I was sitting next to called her friend over to sit down. She pushed passed the people, including the quite large foreign man, and sat down next to her friend. For those who have never been to Korea, this pushing ans shoving happens A LOT. The pushing isn't part of their culture, but not saying excuse me is part of their culture. They're not pushing past you because they want to; they're doing it because they need to do it. A lot of people don't say "excuse me" or "I'm sorry", but I can accept it because I'm living in a different country where the dominant culture is different.
Now, I am side tracked. Ok, the lady sat down, and this large white man began shaking his wet umbrella in her face and yelling "ya/ 야 ",which is really rude in Korean,and then proceeded to tell her, "Say excuse me! Stupid shit. If you touch me again, I'll beat the shit out of you. Fucking bitch. Stupid shit." Please excuse the language, but this is what he said word for word. I was shocked first of all, then I was ashamed. We were on the bus, touching someone during the start of rush hour is inevitable. It is public transport. You pay less than one dollar per ride with three free transfers in an hour. What kind of personal space do you expect? After walking a bit, I was angry because it's d-bags like him that make people think that foreigners in Korea are d-bags. I wanted to get back on the bus and tell him these words: "Who do you think you are? You are living in another country, and the dominant culture isn't the same as yours. You shouldn't force your culture onto another because we are trying to get past the era of racial supremacy and colonization. You live in a different culture, and you chose to do it. So, you should accept their culture. After all, it's their government or their salaries that pay your salary. If you don't like the way you are being treated, you should just leave instead of rejecting someone else's culture." Sadly, I couldn't think of all of this while I watched in shock and horror as he cursed her and shook a dirty wet umbrella in her face.
The more I think about it, he was one of the least adaptable and larger people I've seen in a long time. If we were still in the caveman times, he would have been eaten by a wild animal because he can't out run them, and he isn't smart enough to outwit any other person. While he may have been bigger than me, I could definitely outrun, outsmart him, and/or kicked him where it hurt in the event he did try to "beat the shit out of" the passengers on the bus including me because he assumed I was also Korean. Poor stupid bastard.