Language Incident In Hongkong

The incident that I had is when I was in Hongkong. It was morning and I wanted some fresh air so I went outside my house and had my orange juice. While I was drinking I heard shouting at the background and I turned around and there were about 5 people who were Chinese shouting in their language and I did not understand what they were saying so I just turned around and I realized that I was the only person that they were talking to because there were no people outside my neighbor’s houses. They were tourists from China and they were lost and of course I didn’t know how to speak Chinese because I’m not from Hongkong, I only lived there. I came up to them and asked what was wrong and they just started talking to me in Chinese and I didn’t understand any word that they were saying. After that I told something to them in Chinese which I don’t remember now because it was a long time ago and they shouted at me in a rude way and I started shouting at them as well cause people can’t just shout at you for any reason. When a women came she had an American accent and she looked Chinese, when she saw me quarrelling with the tourists she asked me what I said to them and I told her of course, after that she started laughing and I asked her why she was laughing but she was more focused on the tourists so I had to let go of my question. The lady was explaining something to them and the tourists just started laughing as well and they said sorry to me which was a very polite thing to do. When they were gone the lady told me that I said a swear word to those people and I felt bad but it went away when she told me that she explained to them that I was not Chinese and I wasn’t from Hongkong. I didn’t know that it was a swear word because a teenager told me that the word means hi in Chinese, so it is clearly not my fault or maybe it is but in my opinion, it was only an accident.