I don't see this as a "self defense" case. I believe it is the use of deadly force to prevent a felony (armed robbery,) which I believe is legal in Florida. Either way, justice was served by an armed populace.

"All that the South has ever desired was that the Union, as established by our forefathers, should be preserved, and that the government, as originally organized, should be administered in purity and truth." – Robert E. Lee