I hope you are still working as a LEO, if not, please come work in my town! If you have moved on from LEO, I hope you at least participate in your states LE academy and pass on your wisdom. We need thousands more like you.
I hope that if I am stopped by a LEO on the worst day of my life - the one were I get fired, my wife leaves me, I find out I am bankrupt, and my dogs have run away - that it is Frank or a Frank trained LEO that stops me, if it is Jhands or somebody like him I will probably be killed....Even though I have never actually hurt anybody in my adult life. (I have a tendancy to be verbally argumentative, am a big guy at about 260lbs and a weightlifter/martial arts student, and a very emotional person)
As far as both scenarios that originated the thread. Same answer for both, if I believed that I or my family is in imminent danger of death or severe bodily harm I am going to use any and all means to stop the threat as quickly as possible. Civil and criminal charges be damned at that point. My family will be protected.
Somebody crazy enough to break into my house after hearing my booming voice shouting "I have a gun and fear for my life, if you come through that door I will shoot you" is a threat and will be shot. The castle rule applies here I believe that I dont have a duty to retreat in my own home. That is not to say that if it was safe to retreat and I could safely get through the situation without killing somebody, well I would always choose not to take a life if I dont have to... We do have our plan for home defense and have practiced it. Honestly now though I dont know if things would work that way at all. As I heard one guy say, "Everybody has a plan till they get punched in the mouth".
As far as the BG making a beeline for me or my family members. Totaly situational. First choice is retreat, I could pick up both my kids and run like hell if I had to. My wife also studies fighting - she is 6'3" and placed at least 3rd in every tournement she has fought in, grew up in a large family (fighting all the time), was the kid in school that beat up the bullies... I would probably have to convince her to retreat instead of breaking the guys skull on the pavement...