The fallacy with the line of thought that a round that may pass through a bad guy and hit a bystander so we should use a round that penetrates less has to assume that every round you fire is going to hit the target. If there is a bystander in the line of fire and you miss the point is moot.
The reality is in a high stress situation with a target that is moving and shooting at you, you are hopefully moving to cover, the encounter is likely somewhat of a surprise and adrenaline is pumping you are most likely to miss the target I don't care how close you are. Shooting have been tracked for decades and even with training getting better the percentage of rounds fired that hit the intended target have consistently stayed bellow 20% from contact to seen yards. That means 80% of the rounds fired missed. When the distance increases above seven yards the percentage drops even more.
I don't care who you are or how much training and practice you have it is, to use Archanglecd's fraise, irresponsible to assume every round you fire is going to hit the intended target.