What does a good Samaritan act have to do with a self defense situation? I thought this had to do with when one acts to help and has good intent, if they do something wrong accidentally they can't be sued. Am I missing something there?
As far as rendering aid I think it would depend on the situation, but in most situations it's not going to be safe to render aid. For instance I personally would not try to put a tourniquet on someone who is still conscious and has a knife or gun near them that just tried to kill me. Besides that depending on the situation what could one really do? I don't carry a tourniquet, quick clot, or IV fluids with me around town. I suppose one could do CPR if the BD was unconscious in some situations, but that's not going to do a whole lot of good if you just put a 45 cal through their heart. As far as I understand EMT/Paramedics can't just go into a situation where a gun or knife has been used until the scene has been cleared and determined to be safe by LEO.
I think there is some confusion with the whole shoot to kill, when to shoot thing. I have heard a person say that they were told in there class to "shoot to kill." I think there is a difference here between the law and what happens in court when things are portraits certain ways. I think the shoot to kill thing comes in when people hear others say, "I would just shoot the BD in the leg so I wouldn't kill him/her." If you shot someone in the leg just to injure them, that may look bad in court, since you should only draw your weapon when lethal force is immediately necessary. To me you would only draw your weapon when lethal force is immediately necessary, and that means stopping the threat as quickly and efficiently as possible to save your life. The way to do that is to aim for the "kill zone." Now I think this could depend on the situation as well, but when you have a gun pointed at you or a person with a knife in arms reach and trying to kill you, you don't "shoot them in the arm so they don't get hurt bad." You aim or attempt to aim where you are most likely to stop the threat immediately, which isn't the extremities or bowels. If you happen to fire three shots and only one hits the BD and it hits him/her in the leg and he/she is no longer trying and able to kill you then of course you would not point the barrel at their head and execute him/her.