
I understand the reasoning, I understand why there should be a punishment but murder the "rat" is obviously not a solution. Not only I think the reason for his death is extreme, that quickly can go wrong as well. Someone can incriminate someone else and now they're dead and there's no going back once you know the real culprit.
Well... we did knew that in the first chapter Guwon killed the guys he thought as useless and only spared the life of the teacher because of that exact use that Guwon attributed to him
Fr why are people surprised, we've known he's a killer