Via Gusts of Popular Feeling comes a Korean news report about a foreign hagwon teacher who is driving a scooter and reacts angrily to being cut off by a Korean driver. He later pulls in front of the car to stop the driver and then punches him in the face.
Video of the incident can be seen at this link. Not that it is a good thing to try in the first place, but considering all the cameras in Korea it would be hard for a foreigner especially to get away with an assault like this.