Food for thought. As a matter of law, LEOs are not obligated to protect citizens. I think that has been made clear in any number of courts. So I assume that, legally speaking, citizens are under no obligation to protect one another. Therefore I believe that if you see a person in danger you can walk away from it legally. That takes care of the legal part.
Then comes the upbringing part. Depending on your upbringing you may or may not see it as an obligation. My guess is that big city kids will be brought up to stay out of other peoples problems more than small town and country kids. That is of course a broad generalization, but I bet it is true most of the time.
Then comes the obligation to your own family part. If you have dependents you owe more to them than you do to strangers (in my opinion) so that helping strangers is OK as long as it is not going to interfere with remaining alive and in stable condition for your dependents. This one gets mixed in with the pure survival part of not getting into situations that will end with your death.
I think it boils down to what are the odds that you will not make things worse, that you can actually help, and come through alive and healthy. Weigh those factors and you should get the answer to go or no go.
‘‘Among the many misdeeds of the British rule in India, history will look upon the act of depriving a whole nation of arms, as the blackest.’’ ~ Mahatma Ghandi, "Gandhi, An Autobiography", page 446
‘‘The great object is that every man be armed. Everyone who is able may have a gun.’’ ~ Patrick Henry