Or there might have been two people killed. Or a bullet may have gone through a wall and killed yet another innocent person, because God does love Him some wacky physics. Or he would have never gotten it drawn in time, unless he happened to be holding it when she came through the door, and they would have found the gun AND the pot in the their search and labeled him a drug dealer. Plus if he had tried to shoot back, she could have claimed self defense, even though it was his apartment.
Also, fuck the NRA.