“If you are the one who started the argument and things go bad, you forfeit the right of self defence.”
No. It depends on the chain of events from the start to the crime. There can be intervening events that turn it around, making the initial victim, now, the defendant.
I don’t know what state you are in nor what you are a Sgt. of, but in NC and I would suspect in almost any state that proving the chain of events would be so complex, difficult and suspect that the shooter would be doomed.
For instance, in NC they teach with a video that one can start a fight and at that point would be the aggressor.
But then the other guy pulls a knife, which changes it from a fist fight to a fight for life. They teach that at this point the aggressor has to back off and protest that he gives up and is out of the fight. If the guy with the knife does not quit, then the guy who was the aggressor originally can shoot.
That all sounds wonderful on paper, but in fact who is to say since most fights either occur between two with no witnesses or in front of witnesses who are prejudiced to one side or another.
Throw into the mix a prosecutor like the jerk in the Trevon case or a Nyfong and the defendant’s protestation that it escalated beyond his intentions will not save him.
It is a lot smarter to never appear as the aggressor, even in a non threatening way.