Depending on how old the cub was when they adopted it and how well they treated it, I might have let them part ways peacefully. Evil Overlord List item 48 says “I will treat any beast which I control through magic or technology with respect and kindness. Thus if the control is ever broken, it will not immediately come after me for revenge.”
There are real-life examples of this; here’s one from a BoingBoing post in 2017.
Now if they mistreated it and/or didn’t try to train or bond with it, having it maul the character as a going-away present IMO sounds perfectly reasonable.
