No kidding!

I'd want the situation to end as quickly as possible, because when authorities arrive, they do not know who the good guy is and who the bad guy is.
Even if it ends quickly and you are the one who makes the 911 call reporting the incident, the police might handcuff you and take you for questioning until their investigation has gotten a sense of what happened. They'll almost assuredly take your gun as evidence, temporarily, too.
But it won't even be that good if you've still got a gun in your hand and are firing it when they arrive. Better to make shots count...as has been said, don't obsess over it like you're making a 25 yard target shot, but be deliberate.