People should in all good sense retreat if and when possible.
They should not leave safety and confront a threat.
Property crime is not justification for murder, and whether you want to believe it or not, sneaking up on a guy who came into your home and shooting him is homicide. Legally justified, but still a homicide.
Engaging in an in the home gun battle because a person finds an intruder is dangerous to EVERYONE WITHIN A MILE RADIUS.
In my thoughts, an armed citizen should retreat where possible, contact the law, and then, if the effort to resolve the situation without shots being fired fails, then there is no option left, and that citizen should make every effort to put the intruder into a hole.
It would be interesting to see stats on two things:
First, how often people died in their own homes during a gunfight, who may have had other options for safety.
Second, how many people have died over the history of mankind because they entered a house without evil intentions?
We had a retarded kid up the street that was 6 feet tall, and solidly built. One day, I caught him creeping around the neighbor's house with a toy gun, all alone, playing cops and robbers. he even opened the gate and went into their enclosed porch. Castle doctrine would have allowed my neighbor to kill him instantly. If his parents had been so stupid that he had a pellet or bb gun without a red tip, and he had done so at my house, he might have died if I stretched the meaning of the castle doctrine. But, if I had just stepped away from the windows and called the cops, nobody would have been hurt.