Abt the little brother (who i truly like and hope he appears again), his unguarded manner got him into REALLY serious trouble. In playing the game perfectly, Dowun actually spared his brother’s life by completely submitting to the King. It was the only way out. And the FL at the time was too powerless to do jack shit to save Do-gyeol no matter what she did. Stepping back and allowing the punishment was her only real choice. Now that she’s in power, she can bring little brother back to the palace and protect him, even from Dowun if necessary. Dowun has made a big mistake though - he lied to the FL. He should have submitted to her about the convoy and Baek Han immediately. His own emotions drew him into error, the hypocrite. Had he supported her decision or even been merciful himself about the bodyguard, things would have gone better. It would have shown true power to spare Baek Han.
If you ever read any books about the life of Elizabeth the 1st of England, you see EXACTLY why a female monarch could not trust a man near the throne hundreds of years ago. I learned a lot about diplomacy from studying ancient queens/women in power.