This is a case that needs to be studied in depth, regardless of the final verdict, There are a number of issues here that could have a huge impact on all our safety in the future.
Issues like should a citizens watch person be armed, this is a huge subject of what rights convey. Many areas, or firms hire off duty police officers, and some do not allow them to be armed, while on duty. Having a permit to carry a weapon for a citizen, and then using it to arm themselves during a citizens watch patrol, is something we need to address. As cities and other jurisdictions try and save money by cutting back on police, things like a citizens watch program become more important. But carrying a weapon with minimal training to protect yourself, and carrying a weapon in furtherance of duties like a citizens watch, are far different.
For instance a carry ability in Fla for your personal weapon does not allow you to carry a weapon as a professional bodyguard, or even a guard. Both require much more training, less than police officers get, but far more than a civilian carrying a weapon for personal protection. Making the decision to use a weapon is one of the toughest things for a police officer, let alone a citizen watch. Which is part of the training you need, pulling a weapon of any type can have huge influences on the psychological well being of both the person pulling the weapon as well as the person having a weapon pointed at them. Both can act in very (for them) uncharacteristic ways. That often lead to over reactions on both sides.
Other issues, are the protection of a civilian watch person, it is a real concern, but I think most police and judicial folks would rather they observe and report, rather than putting themselves in actual conflict. For most people, and many will argue even police, a weapon tends to convey a feeling of power and control that makes for decisions that can lead to to incidents like these. The word defense takes on very different meanings when you are in a defensive posture, than when you are actively moving toward a person.
I think the stand your ground law is fine for self protection, but not for a civilian acting under any color of law.
I would like to hear others comments, not of the actual case as much as the over reaching issues.