While I can to a degree relate to the TL's disappointment, I can't help but feel bitter. I mean, this mess was only prevented because the senior knew about Woon Hyun's true identity, and not because he also viewed Sanghyuk's actions as abhorrent.
If Woon Hyun really were just a powerless scholar with a stronger than average sense of justice, his life might've already ended.
Then again, is it really a good move to slay scholars left and right when you've obviously come to the Murim Alliance for help and advice? Hmm...