Sure, that's the smart thing to do, but my question is more around what is the legal expectation regarding the decision you make. If I'm just holding a knife and I ask for your money, I technically didn't say I was going to use the knife to stab you, but you made that assumption based on the context of the situation. Do we as citizens have a legal obligation to get clarification from the person that they intend to do us harm with that knife if we don't give them the money before we decide what is an equitable reaction from us? that's more what I'm concerned about.

That's your upbringing. Some of us were raised that it's better to be killed than to surrender. The crooks know that. They sense it. So they choose their victims carefully.