Well, being in Canada... I cant carry
BUT... If I could and was...
I'd be a lot like a couple people that's posted on here, and try to avoid taking a life as much as possible.
If the robbery had progressed to the point of a little rough housing and he was on his way out, I'd let him go.
If he was beating said old man (or my father like the scenario plays out) I would draw give him an ultimatum (very short and strong worded)
The end of that story would play out and the decision to pull the trigger would depend on if he complied and took the easy road or not.
I mean that's an ideal.... In reality it could be taken a different way and skipped right to the non easy way due to emotions and adrenaline.
Scenario 2 is something similar to a situation I was put in at one point in time. (Except with a knife and not in a car) in which the guy trying to rob me (knife vs knife) got cut up pretty bad, and I got a couple stitches here and there.
Gun wise if I could do so (due to his hands being on said firearm already) he would be immobilized. I wouldn't dump a mag in him because like I said i wouldn't want to take a life, and he wouldnt be doing time because of it.
I mean.... Like scenario one adrenaline might take over and he might be full of core samples.... The first being the ideal.