Judge Hirsch found the disputed evidence was "in equipoise", meaning there was equal evidence on both sides. Thus, he couldn't say Wyche met his burden of proving immunity from criminal prosecution under Stand Your Ground by a preponderance of evidence, and the case had to go to a jury. At the jury trial, his ruling cannot be used to prevent Wyche from obtaining a jury instruction of either immunity under Stand Your Ground or traditional self-defense.

Judge Hirsch's conclusion:

The record before me is silent when it most needs to speak. There is general consensus regarding a confrontation between Wyche and Berry, general consensus that Wyche ran from that confrontation and that Berry followed. It is there that the narrative ceases. Did Berry, or Berry and his companions, hunt Wyche down and present him with no choice but to kill or be killed? Or did Wyche arm himself and then turn upon Beny at a time when Berry had broken off the chase, or was at worst offering a reprise of the chest-pounding in which the two young men had engaged at the outset of their conflict? The record does not tell me. I can draw no conclusion. And because I can draw no conclusion, this motion must fail. The evidence is in equipoise. The defendant has not met his burden of proof.

The opinion is 16 pages and not easily cut and pasteable because it's a faxed copy. I was able to OCR much of it, and condensed the relevant legal points here. Any typos are the result of the conversion process and not Judge Hirsch. Here's my synopsis, but I suggest reading Judge Hirsch's words.

Self defense is an affirmative defense to the crime of homicide. It has the effect of legally excusing the defendant from an act that would otherwise be a crime.

Stand your ground is not a defense, but an immunity statute, providing immunity from criminal prosecution. It is a bar to prosecution (and yes, arrest.)

A defendant charged with a crime who wants to raise Stand your Ground files a motion to dismiss claiming stand your ground immunizes him from prosecution. Here is a typical motion, filed in another case in December, 2011. Here's another filed in January, 2012.

A hearing is held before trial. The burden is on the defendant to prove by a preponderance of evidence that stand your ground immunity applies.

The judge weighs the facts. If the judge agrees the defendant has shown stand your ground immunity applies by a preponderance of evidence, the charges are dismissed. The defendant can't be prosecuted.

If the judge finds the defendant hasn't met his burden, (including if the disputed evidence is so equal on both sides the judge can't decide one way or the other) the case goes to trial to be decided by the jury. At trial, the defendant can still argue both self-defense and stand your ground immunity -- he only has to establish some evidence of his theory, which can be just his own testimony, that he acted in self-defense.

The prosecution must prove his guilt at the jury trial beyond a reasonable doubt. Which means, if the defendant raises self-defense or stand your ground at trial and gets the jury instruction, the state, which has the burden of proving guilt beyond a reasonable doubt, must disprove self-defense. If the jury has a doubt, the defendant must be acquitted.

If, at a pretrial hearing, a defendant meets his burden and establishes his claim of immunity by a preponderance of the evidence, any charge as to which the immunity applies would of course be dismissed. If, however, the court finds that the defendant has not met his burden, the court's ruling has no preclusive effect.... Such a defendant would still be free at trial to plead his claim of immunity to the jury. At trial the burden of proof is exclusively on the prosecution to establish the guilt of the defendant beyond and to the exclusion of a reasonable doubt. To earn an acquittal, the defendant need do no more than show reasonable doubt - a quantum of evidence considerably less than a preponderance. And any attempt to bar a defendant from asserting a lawful defense based on the trial court's ruling that the defendant had not sufficientlv established that defense at a pretrial hearing would no doubt run afoul of the defendant's constitutional entitlement to a fair jury trial, see U.S. Const. amend VI; Art. I Sec16, Fla. Const.

A few other quotes that may be helpful:

If the facts are as the defense claims they are, Mr. Wyche need not rely on "Stand Your Ground;" the common law would justify him. The common law justified a defendant who discharged his duty to retreat, but was pursued by his nemesis, in using force - even force calculated to cause death or serious bodily injury - to defend himself. As applied to the facts of the case at bar, the only difference between the law as it existed prior to "Stand Your Ground" and the law as it presently exists is that a defendant can now seek a pretrial judicial determination as to the validity of his act of putative self-defense (which determination, if in his favor, brings the case against him to a permanent end) rather than having to await the decision of a jury of his peers. If the facts are as the prosecution claims they are, Mr. Wyche cannot rely on "Stand Your Ground;" the statutory law would not immunize him. The statutory scheme entitles a defendant to stand his ground. It does not entitle him to abandon his ground, then arm himself, then hunt down his nemesis and kill him, and afterward assert a claim of immunity

The Wyche case, as I said, is factually different than the Zimmerman-Martin case. But I think its explanation of the statutes, defenses, burden of proof and court procedures is quite helpful.

I've excerpted some of the relevant statutes on self-defense, stand your ground, murder, and manslaughter here.

On the issue of bond, in case I don't get back to it soon, here's Judge Hirsch's decision in Wyche after holding an "Arthur Hearing" finding Wyche was entitled to bond. Again, it's a good explanation of the procedure.