IMO - Gun owners w/ C&C permits are taught that it is their responsibility to not put themselves in the position where a confrontation can occur. If I'm carrying my weapon, it is my duty to avoid confrontation at all costs, because I should not be intentionally getting into a situation where I may be forced to pull the trigger! If GZ were a responsible gun owner, he would have called NEN, alerted them to what he saw, and then sat tight in his truck until the cops arrived! Or just kept driving on to the store, whatever. He should have NEVER followed Trayvon.
Carrying a loaded weapon shouldn't make you feel like it is OK to ante up, which is why I think GZ felt it was OK/safe to follow Trayvon. He may not have WANTED to use it, but he sure felt confident enough to follow Trayvon, a person he felt was suspicious enough to report to the police... the gun gave him confidence.