Ricky, I think your questions are addressed by the Dooley case
CBoldt referred to from May, 2012. Although a District Court case, rather than an appellate case, and probably not of precedential value, it says that at an immunity hearing under 776.032, the defendant has to establish by a preponderance that his use of force was justifiable under 776.012 or 776.013, and that if he provoked the attack, he is not barred by 776.041 from claiming justification under 776.012.
The ruling was unfavorable to Dooley, so it's phrased in the negative, but it gives you an idea what at least one judge says is the burden:
Defendant has failed to prove by a preponderance of the evidence that he is entitled to immunity from prosecution. First, the Court finds that Defendant has failed to prove that he met the requirements of either § 776.012 or § 776.013(3). Second, the Court finds that even if Defendant had satisfied either statute, Defendant would not be entitled to immunity because he failed to prove that he is not barred from relying on the immunity statutes pursuant to § 776.041.
Assume Dooley had the facts on his side, the finding would be the reverse, something like this:
Defendant has established by a preponderance of the evidence that he is entitled to immunity from prosecution. First, the Court finds that Defendant has established that he met the requirements of § 776.012 or § 776.013(3). Second, the Court finds that having satisfied one of the two statutes, he is entitled to immunity because he has established he is not barred from relying on the immunity statute pursuant to § 776.041.
If the state doesn't claim GZ is the aggressor, the 776.041 bar doesn't even come up. If the state makes that claim, this judge is saying that at the immunity hearing, to prevail under the preponderance of evidence standard, GZ would have to establish both that he fit under 776.012 and that he is not barred by 776.041.
As such, in addition to having to satisfy either § 776.012 or § 776.013(3), a defendant who initially provoked the use of force against himself or herself would also have to prove that he or she satisfied one of these exceptions to be entitled to immunity.
This judge is accepting as true that Dooley provoked the attack. But his point is that the defendant has to show he is not barred by 776.041. If there was a dispute as to whether the defendant provoked the attack, I think this judge makes it clear he would say defendant had the burden to establish he did not provoke the attack by a preponderance.
Again that's just one trial judge, but it's very recent and seems to at least address your question, if I’m understanding your question correctly.
At trial, the burden would be on the state.