Dennis, don't know if state law governs or not. I do know part of what you said is correct, if you start CPR, there are rules as to when you can cease. I am a 10 year EMT/AHA CPR instructor. If I am working, yes I am obligated to perform CPR. If I am not working, I am not obligated, but If I thought the person down had a chance, I would start CPR.
Dennis, I think this 200 number you were given, is phony. Neither I nor any I know have ever heard of that kind of number. GLV