If he had only had a gun

In the thousands of right-wing words I have read and heard regarding the Trayvon Martin-George Zimmerman case, one point I haven’t heard anyone make is that it was too bad that Martin didn’t have a gun. Zimmerman had a loaded gun and killed an unarmed teenager. He is hailed as a hero by people such as Ann Coulter and Geraldo Rivera. What if Martin had been carrying a gun? What might have happened then?