Looking in hindsight, always risky, if the prosecution had tried GZ for manslaughter, it would have been nearly impossible for the defense to explain away "they always get away with it".
"They" when all G knew was that T was black, "it" which would have given away George's frame of mind for bringing a gun to a peaceful scene.
They did charge him with manslaughter...a charge which the jury found him not guilty of for the same reasons that they found him not guilty of Murder II. George Zimmerman was attacked by Trayvon Martin for following him. Zimmerman used his weapon to shoot someone who was straddling him and raining blows down at his head. It's one of the most clear cut cases of self defense I've ever seen.
In hindsight, the original Prosecutor, who declined to bring charges against Zimmerman because he felt the case was so weak, was proven to be 100% correct in that assessment.
If Angela Cory had taken her case to a Grand Jury it's almost certain that THEY would declined to find probable cause to take the case to trial as well...something Cory obviously KNEW when she sidestepped taking it to a Grand Jury and took it to a Judge instead...lying about the circumstances of the case to get an arrest warrant issued for Zimmerman. You're going to see the Special Prosecutor Cory get punished for how she conducted this case. They won't be able to do it while she is still in office but those charges will be pending.