I'll be honest, and say I skipped a good thirty pages of this topic. Now, if I'm repeating what someone else said, oh well. The following needs to be noted.
Some people have said "shoot him in the leg." I present to you the Femoral Artery. Sever this bad-boy, and you bleed out real fast.
For those of you that say what would of been better, do note, you weren't being mugged, you weren't punched, you weren't about to be punched again, for all you knew, the next hit would be with a knife, trying to kill you.
The man was in close-quarters, meaning had he shot and NOT killed the assailant, but merely wounded him, the assailant has the opportunity to kill you. That's not something you particularly want.
Now, Hollow-points, as most have said, are meant to kill. They're meant to kill their target, and ONLY their target. When using a gun, you do not want the bullet to pass cleanly through your target, possibly hitting a bystander. Besides, most attackers do not wear body-armor, so armor piecing would of been fairly pointless, and standard bullets don't have the stopping power you NEED in a life and death situation.
As for the eight times, if you claim you've never panicked, then you're an outright liar. When you believe your life is in danger, you shoot to kill. If the target is nullified, and not killed, even better. Just remember, in situations like this, better to of killed, then of been killed. Did the teen "deserve" to die? No. Unfortunately, the poor decisions he made got him killed. That's life, no one said it was fair.