Do I have my cellphone with me? Because I'm going to try to be the best possible witness I can be.
Please Google up my previous rants on the "sheepdog" sheepdip. I am not a cop. I don't want to be a cop.
Scenario #1 might warrant intervention, but by the time I got to where it was taking place that most likely would be offering first aid and summoning EMS and the cops to do their thing.
Scenario #2 is missing all sorts of information. I have dealt professionally (Dept of Corrections) with folks in wheelchairs who were armed and intent on causing hurt/death. In other words - a) there might be a good reason for the behavior of the cops and b) I can be more helpful as a witness than as someone arrested for obstruction of justice.
Scenario #3 is much like scenario #1. Plus, you do not know if the man is actually defending himself from an attack initiated by the woman, do you?
Scenario #4 is a red herring. I cannot have herrings of any type - doctors say they are not good for me. But especially that red herrings are not good.
Scenario #5 makes me wonder just what you might be thinking of doing - going up against a platoon of ninjas with automatic weapons?
Just for fun, how about I add some details and you tell us how you would then respond? You are a single parent with an 8-month old and a 3-year old, and even though you have a decent job that pays a decent wage you have no more than about a week's worth of expenses saved in the bank (actually, sitting in your checking account). Now what would your responses be?