The "big guy" who followed and picked up the shouter would be guilty of assault, assuming his story is true. The "big guy" could go to the "big house."
Shouting remarks out a car window is not a crime.
Having said all that, I did exactly the same thing to a kid on a bicycle about 30 years ago. He swore at my family and me as we sat at a red light. You should have seen the look on his face when I got out of the car and dragged him off the bike and made him apologize. I'll bet he never did that again. I'm glad I didn't get arrested