I've probably missed it, but I haven't seen a lot of discussion about why Zimmerman's lawyer seemed to take Stand Your Ground off the table. At first, that had a bunch of people scratching their head since it seemed like an important and beneficial statute -- but the lawyer indicated that they would not use it.
Of course, as you say, no one needs Stand Your Ground if they are flat on their back, getting their head smashed. In that situation, the shoot can easily be seen as righteous by any rational human.
I think the lawyer indicated that Martin's actions were legitimate even under standard self-defense doctrine. This leaves Stand Your Ground as a backup.
Right. I expect the physical evidence will bear this out.
The statute that contains the stand your ground allowance also covers self defense while retreating, or when unable to retreat.
The lawyer's remark is a reflection of the incident - the incident has no evidence that Zimmerman stood his ground.
There is a thorough discussion of this at Florida's Self-Defense Laws - David Kopel (volokh.com) - March 27, 2012
For now, it should be noted that neither the M narrative or the Z narrative has anything to do with a duty to retreat. The retreat issue would only be relevant if Martin were the aggressor, and Z had the opportunity to escape from Martin in complete safety. Then, and only then, would different state standards about retreat be relevant. Simply put, everyone who has claimed that Florida's retreat rule affect the legal disposition of the controversy is either misinformed or mendacious.
Stand Your Ground means you’re allowed to fight back and not forced legally to retreat.
It could not be applicable in a situation where you are getting beaten lying on the ground and have not possibility of retreating.