The best explanation would be that it was the doing of someone within the Xiao Clan!
Xiao Kuangyun was also furious at this matter, but he only got angry for awhile because he only felt the great pity of losing an obedient and capable slave. He could get that kind of slave anywhere he wanted. However, now he couldn’t bring back Xiao Yulong, who currently resembled neither human nor ghost, so thus his choice naturally fell on the person who was second to Xiao Yulong in yesterday’s “evaluation”.