It's not trivial, dunno about US, but in many (developed) countries around world not providing help to someone (passing around car crash without stopping, if you don't see anyone providing help) has legal implications.
When you are certain your actions will result in the death of someone then I doubt the legal protections of helping someone is as clear cut as you think it is.
Maybe I'm wrong, I don't know all laws of all countries.
Maybe I'm wrong, I don't know all laws of all countries.
I'm hoping a lawyer would jump into this thread.