If woman & man fighting - call 911 from a distance - if help the lady sometimes the lady and guy will both turn on YOU
If gun situation -(as in 15 feet in front of you) pretend you don't see - or you get shot also (Gangland violence on the corner of River and Pahaui street in Chinatown Honolulu)
If knife situation - Twice I tried to help and twice I was the one who ended up with a knife to my throat - Gary Shaylor saved my life twice over by hitting the guy over the head to let me go after I was trying to save James Morrell in Portland.
If fire - I don't know - never been in that situation before.
If medical of course ALWAYS - unless it's a crack addict thief -sub-par human - then I wouldn't bother to piss on him if he caught on fire.......if female then I would tend to look at her as a victim unless she borne 8 crack addicted babies already in the past.
The Good Samaritan helped the stranger because assumed the stranger was a good person who should be saved as opposed to a well known street low-life who keeps popping out crack addicted kids that CPS takes away at the hospital.