I actually think this clip is weirdly revealing. I can't figure out what George Zimmerman is actually apologizing for. If I got out of my car, and a person approached me, punched me in my face, and proceeded to repeatedly ram my head into the concrete, I think it'd be fair to conclude that this person was either trying to kill me, or was showing extreme disregard for my life.
If I then shot that person, I would not apologize for it. I would feel completely in the right. I might even go so far as to feel that the person's parents owed me an apology for allowing someone so prone to unprovoked lethal violence to roam my neighborhood. What would have happened had that person ran into someone else, who was unarmed? If you are so brazen as to brutally assault someone for no reason, you are not merely a threat to me, you are a threat to society.
In my experience, even in neighborhoods with high levels of violence, it is extremely rare to run across such individuals. I've known boys who get together and jump innocent people for kicks--something that's uncommon, but not rare. That is the mentality of the idle pack. Doing something like this solo requires a different kind of constitution. I can think of only one person who I've ever met who would do what Zimmerman is alleging Trayvon Martin did. The last I heard, he was in jail for killing his Dad.