The provision for the SYG immunity hearing should be looked at as a completely different provision for purposes of all this.

Self-defense law in FL, like the majority of states now, does not have a duty to retreat. And yes, that's the general self-defense law that applies no matter what the defendant chooses to do about the immunity hearing.

Generally, the duty to retreat would have come in close to the time he fired the weapon. The old law would have said that before the defendant used deadly force he had to take reasonable measures to retreat if he could. IMHO, I think the legal reasoning in that situation would have been that a person who was pinned down with his head being hit into concrete would not reasonably be expected to retreat so it probably wouldn't have been a relevant point of dispute. (I'm not saying anything at all about this case. I'm just saying that in a hypothetical in which the facts weren't in dispute, that would be the legal reasoning.)