Hi Pax - I don't think my question/reply was out of line. I have a count that I go through each and every time I leave the house (yes, I actually count how many of my must-carry items are on me) and a working phone is part of that count.
I carry a gun, a knife and a phone as part of that list. Many (read most) places I visit in NC do not allow a gun, some do not allow a knife but nearly all allow a phone. It should be part of our "arsenal", so imo, the first lesson to take from this is don't leave phone in the house. This becomes even more important if you are someplace where you feel you might need a gun.
Also, my answer did cover the "what if" that the OP gave, do not initiate conflict and do not even consider a deadly force option unless you legitimately feel that your life is threatened.
So, in order, I would have my phone, I would not aggress and I would use lethal force, provided the situation actually required it.
For what it's worth, I'm with the pizzakilla camp in that I read it to mean that they were not on his property. If they trespassed that I would also opt for "leave my property or I will call the police" and then I would retrieve my phone. If it's inside you can still get to it without losing sight of your would-be attackers and if they close on you then you escalate appropriately.