What if you fired shots in order to protect your children but only managed to shoot innocent bystanders
Does that still make it okay?
No, it doesn't. However, if you killed the bad guy and prevented him from killing everyone...would that be a good thing? Or a bad thing?
And if you did kill the bad guy but killed one innocent person as you did?
I would never fire a gun at a person because the risk of injuring or killing a bystander is too great.
10 people in a room. Only the bad guy has a gun. All the good people die. Result -10 people.
10 people in a room. Two people have a gun. Bad guy starts shooting, followed rapidly by the good guy. Bad guy kills one, and the good guy kills one plus the bad guy. Result -3.
How do you think the other seven people would feel?