If there's one thing Plauche did wrong, it was 180 noscoping the pedo. He could have very easily killed someone else if his timing was a fraction of a second off. And even if everything went perfectly, there was always the chance of the bullet exiting his skull and hitting the person on the other side.

Personally I would have recommended a shortsword to the abdomen followed by a quick pull upwards. Safe, easy, and sends one hell of a message.