Tensed up by seeing a fight

[Kicks]

I was once walking through a parking lot when I saw a man in a car grab the lady sitting in the passenger seat by her hair and started punching her head while still holding on to her hair (sort of like a yo-yo). I went to his side of the car and started shouting and banging on the roof leaving some dents. He looked scared to death and let go of her. The lady got out and walked off. He drove off in the opposite direction. I never learned the story behind what was going on.