[b](b) In good faith, the person withdraws from physical contact with the assailant and indicates clearly to the assailant that he or she desires to withdraw and terminate the use of force, but the assailant continues or resumes the use of force.[/b]

There is absolutely no evidence George Zimmerman ever tried to withdraw from the situation, that he signaled this to Trayvon, that Trayvon hit him unprovoked, or that Zimmerman was about to die. From what we know about his injuries they were fairly mild, no indication deadly force was used against Zimmerman.

In Johnson v. State, The question was to whether FS776.041 should have been included in jury instructions. The instructions as given during the trial included FS776.041(2)(a), the exception you claim can't apply due to Johnson. The appellate court upheld the instructions as given, including the section starting "(unless)Such force is so great. . ." This would affirm, rather that override the exception to "use of Force by Aggressor".

As stated by others here, the older precedents would also not apply, since they were made under different statutes than apply now.

"776.041 Use of force by aggressor.—The justification described in the preceding sections of this chapter is not available to a person who:

(2) Initially provokes the use of force against himself or herself, unless: …

(a) Such force is so great that the person reasonably believes that he or she is in imminent danger of death or great bodily harm and that he or she has exhausted every reasonable means to escape such danger other than the use of force which is likely to cause death or great bodily harm to the assailant; or…"

So even if Z HAD initially provoked TM he was justified in using deadly force in self-defense if he "reasonably believed he was in imminent danger of death or great bodily harm". (Barring a contemporaneous independent forcible felony by GZ – section (1), which I've omitted as it cannot apply in the absence of a charge).

There is no discussion of consideration of two people changing the path that does not cross another. A player had a chance option of dialogue; chose to tress pass in ones right to life. The outcome need not be, what is at hand. A simple conversation would have not marked the benefit of those who would dialogue in consideration.

There is a result that need not be discussed, had the hands of one, not trespassed upon the contact of another. Words, anger, posturing breaks no bones. Why is this case so easy to be understood to benefit the very association, that relies upon this type of action for its market place. It is clear the members of an association, wishes to make appearance of license, of which it is of colour, but not of the great law upon this land, well traveled.