Expected by whom? Your pastor? A Judge? Some dirtbag's family? Your own conscience? Your employer?
In this hypothetical situation, did you run out of ammo or something?
If it's come to the point of shooting someone, then I am in fear for my life or great bodily harm and I expect that I could reasonably explain that. We're adults and we know why people break in to houses, do stick-ups, etc. and we know who commits these types of crimes. Not only could I likely articulate why I shot a stranger who broke into the house where my family's sleeping at 3AM, I'm pretty sure I can articulate why I don't want to go mouth-to-mouth and get elbow deep in blood and guts of someone who just committed a violent felony in my home, may or may not still be armed and dangerous, and is likely a drug and disease filled junkie.
Besides, many states have laws that protect you against civil suits in lawful self-defense cases. Regardless of how upset they are that their family member won't be finishing their research on a cure for cancer, they would be out of luck on their big lawsuit payday.