Yes it worked out well in this instant. What if the fool was high on PCP for example, if your afraid to take a persons life and rather shoot them in the leg instead of center mass, your asking for nothing but legal trouble in the very least. As well as the possibility that your leg shot does nothing more than giving the guy more time to kill more people. The bad guy if not already pulls his gun and has the intent of killing you. To say I will shoot him in the leg WILL be used against you and you will be seeing the inside of a jail cell if it is successfully used against you in court. You are playing with fire, if you feel your life is threaten, you use lethal force every time . If you're dealing with what cops call an ODC (ordinary decent criminal), then most likely nobody is going to get hurt; but once things tip over that edge (and it can happen at any time, with no warning), you are effectively a dead man already, unless you act to prevent that from happening.
It should go without saying, that you should NEVER comply with a criminal who has invaded your home, private office, or car; as these are automatically at an escalated level of violence (because they are emotionally violent and risky acts as well as physically). In fact, if you have effective means of resisting, and are not risking others unduly in the process, I believe you should never comply with a criminal period.
Do not be passive in the face of escalated violence. Once violence has escalated beyond the point of simple assault, you are a dead man waiting for the bullet. Realize that and fight back in any way you can, whether you are armed or not. Remember, ANYTHING can be a weapon. If violence does escalate, respond immediately and decisively. Shoot to stop, use your knife to stop, use your fists, your feet, your teeth, use whatever it takes to end the threat as fast as possible. This isn’t Hollywood, this is your life, and the lives of those around you. You don’t give warning shots and you don’t tell someone to drop their weapon; you shoot them in the head or center chest (or both). Remember though, at this point there is already a high likelihood that you are a dead man if you DON’T do something, so sitting tight and waiting to die isn’t a great idea or trying to give that poor robber, a chance to change his mind by a warning shot or a shot to their leg is going to get you or someone killed.
If you are forced to pull your gun the robber has escalated the violence past talking or given the opportunity to run and deserves no more quarter, you chose to pull your gun in self defense so use it or DON'T CARRY AT ALL. Pulling these tv / movie 30 second guns draws and trying to talk to them is going to get more people killed because you cant use proper force to stop them. YOUR NOT AN FBI AGENT OR A COP, ITS NOT YOUR JOB TO TALK THEM DOWN OR GIVE THEM A MOMENT OF PAUSE TO THINK. Allow the cops to do their job if they are present, if they are not your ONLY job is the safety of yourself and of those around you. When you draw your gun you have made the choice that your actions may kill the person because THEY escalated past the point of no return. If you cant see your actions resulting in the death of a criminal because of them forcing your hand to act, you have no business carrying anything.
To me and others you are playing with the lives of those who don't have that ability or the willingness to take a life. They rely on you to have the ability to kill if necessary in hopes of saving others and yourself, if your intent in drawing your weapon is to warn said criminal or hopes of just having to wound them you DO NOT UNDERSTAND the great responsibility you have by choosing to carry. No one wants to have to kill anyone, but if they force me to draw my weapon and my shots only critically wound them then great, they will have their day court. If my rounds kill that person then so be it, I am not pulling my gun to wound. I am pulling my gun to stop said criminal the fastest way possible and shooting them in the leg does not stop them nor does giving them a warning shot. Doing either still allows them to have the means to kill people. More than likely they will start shooting as soon as you draw. The I will give a "warning shot or just attempt to wound them crowd makes me extremely nervous, the fastest way to stop a criminal is causing the most internal tissue damage to their organs and life support as possible. You don't get that from a leg wound period.