I was driving on Main Street toward 495 between 59 Ave and 60 Ave, I saw an Asian man chasing these 3 teenagers, then the one whose jacket sleeve with some orange strips threw a cup of drink to the man. The man got wet on his shirt and pants, stopped and let those teenagers walked away turning into Horace Harding Expressway. 

I don't know what really happen, I took the picture of the "attackers" just in case there was some criminal activity.