Given the variety of state laws, it's impossible to speculate as a non attorney, and even the attorneys will be fighting over this one.
Virtually anywhere in the western world, though, and particularly in English speaking countries, self defense laws all stem from the same common law doctrines, and are therefore usually similar in their most basic forms.
In essence, it is legal to use reasonable force to defend yourself if you are attacked, and didn't provoke the attack in any way. The use of deadly force is generally deemed legal if a reasonable person, knowing what you knew at the time, would feel that they were in danger of being killed or seriously injured.
The biggest complication in this case is the disparity of force. A gun is generally regarded as the most lethal means of defense, whereas mace is non lethal, and rocks are generally not life threatening. That's not to say that they can't be part of a life threatening attack, but in a case where there's that much disparity of force the intent of the attackers is key, and it's always about what you can prove. In general, the attacker must have the means, motive, and opportunity to kill or cause serious injury. It will likely be argued that the attackers didn't constitute an immediate deadly threat. The means were sketchy, the motive unclear, and the opportunity not that great since the police and many bystanders were present.
What it will ultimately come down to is what the jury finds to be reasonable. I would vote not guilty and hang the jury even if it meant living sequestered in a hotel room and eating pizza for weeks on end. In decades past, any reasonable person would have done the same, and probably thought he was nuts for not shooting. Unfortunately, the average person these days is so far beyond mentally ill you can't trust them to be reasonable even in the most cut and dry case possible.
Virtually anywhere in the western world, though, and particularly in English speaking countries, self defense laws all stem from the same common law doctrines, and are therefore usually similar in their most basic forms.
In essence, it is legal to use reasonable force to defend yourself if you are attacked, and didn't provoke the attack in any way. The use of deadly force is generally deemed legal if a reasonable person, knowing what you knew at the time, would feel that they were in danger of being killed or seriously injured.
The biggest complication in this case is the disparity of force. A gun is generally regarded as the most lethal means of defense, whereas mace is non lethal, and rocks are generally not life threatening. That's not to say that they can't be part of a life threatening attack, but in a case where there's that much disparity of force the intent of the attackers is key, and it's always about what you can prove. In general, the attacker must have the means, motive, and opportunity to kill or cause serious injury. It will likely be argued that the attackers didn't constitute an immediate deadly threat. The means were sketchy, the motive unclear, and the opportunity not that great since the police and many bystanders were present.
What it will ultimately come down to is what the jury finds to be reasonable. I would vote not guilty and hang the jury even if it meant living sequestered in a hotel room and eating pizza for weeks on end. In decades past, any reasonable person would have done the same, and probably thought he was nuts for not shooting. Unfortunately, the average person these days is so far beyond mentally ill you can't trust them to be reasonable even in the most cut and dry case possible.
