OOPS BANG! Unintentional Shooting = Self-Defense?

A New York City liquor store owner finds two men stealing, and shoves them out the door onto the sidewalk. A verbal dispute continues, and one of the thieves charges at the store owner standing in his doorway, punching and kicking. The store owner then follows the thief out onto the sidewalk, and throws a right hand at the thief. In that right hand, however, was a pistol, and it discharges as the blow lands, resulting in a gun shot wound to the thief. Presumably the shot is un...