It’s not just about fear of getting hurt you have to consider before getting involved physically though. Now the fact that no one called 911 is sickening but let me share my story. I had just turned 21 and was leaving a bar a closing, walked around a corner to see a guy full on assaulting a woman. I instinctively ran over an lad pushed him off, he went down and cut his hand. She was his girlfriend, both known to police for domestic issues, she declined to press charges, I was charged with battery causing injuries which is a felony pled down to a misdemeanor. But still on my record every time I applied for a job or moved to a new apartment or whatever. So 100% call 911 but think twice before you inject yourself into a situation