A while ago I was walking down the street when a man on the other side was shouting and swearing at a woman, using very bad language. She had a shopping bag with her, he pulled it off her and threw it on the ground.
I shouted at him that that sort of language was offensive, and he realised I was there. He started to leave, and I told him to pick up the shopping which was lying on the road.
Amazingly he did, and pushed it back at the woman, and then left.
I did not go to the woman, because she appeared to be drunk or drugged, and that was what I didn't want to get involved with. I did all this before I thought, afterwards I realised what could have happened.