As a lawyer, I can tell you that is not true.
It differs from state to state - and it's even codified as part of Stand You Ground (Florida Statutes 776.041; which is different than common law) - but the attacker can declare the right is over, physically separate, stop - and if the other party continues, the initial attacker can draw the gun. 776.041 is even tougher. If you can't separate because you can't retreat, you can fire.
I'm just telling you the law. Read it; don't believe me. I learned it in law school years ago and I've read it multiple times since Zimmerman.
You are correct - while most self defense claims (it varies State to State as you pointed out)are somewhat predicated upon being the victim of an attack and not the initiator of the attack - this is not the case with the “stand your ground” law.
My post #50:
And apparently according to the “stand your ground” law as written - one CAN start a fight, determine that they are losing said fight, and then use deadly force to stop the fight.
I don’t think that SHOULD be the law - but apparently it is (for now) in Florida.