Even if Katou doesn't, can't get up, the next blow is definitely coming. Katou's hunched forward, but between being breathless and stunned, it shouldn't be too hard to shove him backward enough to get a good shot at his face. Stooped over and practically straddling Katou's body in order to get in close enough proximity, Kira punches him in the face, the corner of the mouth to bloody up his lips, just once.