CCW Instructor: Don't tell the police if you had to use your weapon in self defense.

I've taken two CCW classes in my life. The first one to get the permit and the second time to get it renewed. My second class had an instructor who has taught thousands of citizens, is a former LEO and police instructor. He also boasts how he has had over a dozen judges take his class and all have approved of his course and methods. He teaches something that I think goes against almost everything many of us have heard or read: Do not tell the police if you had to shoot in self-defense unless it was in your home.

The moment he said this the class gets stirred up in objection but I couldn't help but think there was some truth in his reasoning. He gives an example scenario:

You are walking to your car late at night in a parking garage. A man lunges at you with a knife from behind a car, his intent is without question. You draw your weapon, shoot and kill him.

He says to just get in your car and go home and live your life. Don't even call your lawyer. He gives a few reasons why:
1) You have no legal obligation to report this incident. You are protected from incriminating yourself and there isn't a single law being broken by leaving a dead or dying man who tried to attack you. He could have buddies nearby, HIV, or still be a threat even if wounded.
2) Even if there are witnesses or security footage, let them call the police. Let them put a out a description asking to meet with this person unknown for questioning. Again, you have no legal obligation to identify yourself.
3) If you truly acted in self defense, witnesses testimony or security footage will likely show this in which case the police aren't going to spend much effort finding you.
4) By calling the police you have everything to lose. You are risking a trial. Losing everything to a career motivated prosecutor or civil trial from the criminal's family. By not saying anything you haven't lost anything and chances are will never be contacted.
5) If you are identified and the police show up at your door. Could be six months later. Then say you would like to speak with a lawyer. Give your official statement and go home. He had a list of about a hundred incidents where the victim followed this method and it never went anywhere after giving a statement.

After hearing this almost everyone in the class speaks up with objections. What about the court of public opinion? He says that chances are you will never have to go to court if you don't say anything. If you do, what's the evidence? You didn't commit a crime by not saying anything. You can't be found guilty of anything by keeping your mouth shut. Again, you have no legal obligation to wait for the police, to tell them anything or to turn yourself in no matter how much they want to just "talk".

He does make some basic exceptions: If you had to shoot someone in your home and a wounded or dead criminal needs to be attended to. Or if when you drew your weapon the criminal runs away -- in which case its the "first one to call is the victim" scenario.

Now, I do not support his method but I do see some truth in it. But mainly only in the most clear cut cases of self defense, which most fall short of. So what are your thoughts? Is this guy crazy?