The person iniating aggressive contact is always considered the attacker. It’s unlikely that an unarmed kid is going to be the one to initiate aggressive contact with somebody with a gun.
Unless Zimmerman was carrying it in a hip holster, it's unlikely the yute knew he had a gun.
Yep but how do you know which one started the aggressive contact. Hint you do not know you are assuming it was Zimmerman. Following someone and asking them what they are doing is not aggression.