If the bolded is accurate, that is cause for concern regarding FLA.
Most states, like my own, simply remove the duty to retreat. I've been concerned with Florida's version myself, however, as it appears to be a lot looser than most.
See, my state follows the same principle that most states do: If you START in the wrong, you STAY in the wrong. In other words, if you walk up to someone and attack them, you're unable to claim self-defense afterward in almost any case, or if you CREATE the situation by committing a crime first, you have no self-defense grounds. Even if you do something relatively minor (misdemeanor) like trespassing then refusing to leave, you lose your ability to claim SD.
The only possible exception is a narrow clause that if you disengage and attempt to retreat, and the person pursues and attacks you, you MAY be able to claim SD at that point (but it's iffy).
FLA law (not just SYG but their revamped SD statutes in general) may be loose enough to give benefit-of-the-doubt even in cases where the person clearly sought out and started the conflict and clearly committed the first act of assault... if that is the case, that needs fixed.
But still, I don't think this guys claim is going to fly. You can TRY to claim anything... doesn't mean it is going to happen.