"Stand Your Ground" has been successfully used in cases where the victim was shot in the back

[JoeH]

Depends a lot on which state you are talking about. Here if there is evidence that the person was leaving, i.e. shot in the back, then there is a possibility of conviction on manslaughter charges and civil liability. A group would complicate the issue as it is possible one would have "retreated" and gets hit while another was shot at. There are quite a few states where the same applies, no unlimited home defense.