If Luosang's subordinates had not been brought into the Palace, he could have had them killed to cover this up. That way, he could have given the excuse that Great Shang was trying to trap Luosang. If his sister refused to say a word about it, it would be difficult for Long Yang to sentence her with any crime.
However…
Lu Liangwei did not allow her subordinates to return to the coaching inn, but instead ordered for all of them to be detained at the Palace. This placed Wanyan Jin in a situation where he was unable to take any action.
He collected his thoughts and turned to Long Yang without any trace of emotion. "My dear sister has not learned her etiquettes and has ended up offending Her Highness. I beg of Your Majesty to give her a chance as she has grown up in Danjue since birth and has never really seen the world. I'll make sure to discipline her properly once we return."