They are not using the stand your ground defense and the cases aren’t even similar.
The "stand your ground" defense and the Florida "stand your ground" law are two different things. The law provides for a preliminary hearing in which the judge can throw the whole case out (civil included) if the preponderance of the evidence indicates the defendant acted in self defense. It is not necessary to assert the defense in order to claim the right to the hearing.
Why do they keep taliking about “stand your ground” when Zimmerman shot from the ground? You aren’t “standing” when you’re off your feet.