Lmao, when you see the police shoot you always see the suspect drop at the first hit or at least not being fysically cable of continueing fysical attack. Rarely a second one is needed. Yes they empty their gun but that's because they are completely incompetent or because the suspect has a fire arm and still poses a thread.

Your self defense instructor is a trigger happy trainer if he tells you to empty your gun. Every soldier that used his glock on an enemy will tell you 1 is enough, two is to make sure. Make sure they're not armed anymore and save the other bullets for your next target. And yes they are probably still alive but there's a huge gap between being alive and continueing the attack.