Castle Doctrine laws clearly improve the situation of reasonable actors. I mean, it is prima facie reasonable to use deadly force against a stranger breaking in.
Stand Your Ground laws, OTOH, are unclear (to me) about whether or not, lacking a duty to retreat, now also void a duty to act reasonably. My example of joining a bar fight and shooting if things don't go your way is on point.
IF (and it's a big if) a jury finds that Zimmerman, in toto, acted unreasonably in confronting Martin, does the current Florida law protect him once he started getting his ass kicked?
That's the question I'm looking for an answer to.
It's not. A person standing ground and using force also has to be acting in reasonable apprehension.
-- IF (and it's a big if) a jury finds that Zimmerman, in toto, acted unreasonably in confronting Martin, does the current Florida law protect him once he started getting his ass kicked? --
The law is well aware of situations wehre the tables turn, and a person who "started it," then decides to retreat, is not held to be acting unreasonably if he later defends himself against an attack. The "it" in "who started it" doesn't necessarily refer to the entire sequence of events.
If Zimmerman had broken off his chase, and was returning to his truck, and Martin jumped him, then Martin started it. Martin is liable, and Zimmerman 1) isn't in a "stand your ground" situation at all; 2)Martin has a right to use force to defend himself. That section of Restatement does a good job of describing what is "reasonable" as far as apprehending a risk of serious injury; and reasonable apprehension of serious injury justifes the use of deadly force.
The situation of jumping in to a bar fight will be viewed with an eye to why the person entered the fray. If the reason is to break it up, and the person breaking it up becomes a target of force, then there is a right to use self-defense.
A police officer who is breaking up a fight can obtain a right to shoot, depending on the actions of the fighters.
But, if the person entering the fray is intending further escalation, he loses the right of self defense.