Suzi - you did what everyone would like to be able to do but do not for fear of reprisal and weapons.
I don't know what I would have done if I am honest. I might have wished I was a million miles away, or watched some bullying, but I genuinely do not think I could have watched someone being beaten up beside me. A you say, you did what you felt was instinctively right.
I think it is shocking but a modern day phenomenon that people are scared to get into something that is 'not their business' in case they are injured or killed. Weapons are frightening and unless visible are an unknown factor. Television portrays the same violence with people killed. People are afraid, stay back and so the violence is perpetuated.
I was sorry to read you had had such a reaction Suzi. You must have been shaken up inside, even if not visibly. Shame on the man who stood back and let you take the flack. I wondered if he was frozen with fear like many others might be. I am pleased the woman / girl came to sit beside you afterwards.
I think your husband is right - avoid the trains for a while, and let's hope their was CCTV and the police can find them. Sounds like they might already be known to the police.
On a similar note, my daughter when she was 13 had gone to visit her friend's grandmother and was stayovernight. She joined her friend and a group of friends in the very closeby park. While sitting laughing and chatting, a crazed girl came up, caught her from behind and assaulted her badly. She was kicked, punched, her head smashed off benches and climbing frame. The girl was crazed with drugs. She could not get away despite three of the crowd trying to pull the girl off her. It was a tall young rugby player who saw it from nearby who leapt the fence and had the strength to tackle her and get my daughter released. She ran like the wind. He literally saved her. Another girl was attacked in a phone box and her head and body kicked and jumped on so much that she ended up paralysed in hospital (her Mum traced me and phoned me). It was a debacle trying to get the police to find her and deal with her. She was 15 and in so much trouble with a very bad family home background. In the end, my daughter did not need to testify. They dealt with her under other charges. (I cannot remember the exact detail).
But like you did Suzi, my daughter may not have been alive if it had not been for someone having the courage to intervene. I am sure the man will reflect and appreciate what you did for him.
Fx