I think Jude's most definetly gonna sneak back into Faerieland without Carden's approval, but he was probably expecting her to do it.
Madoc knew that Cardan was under Jude’s command, Cardan needed to exile Jude to prove that wasn’t the case.
Cardan wanted to be Jude’s equal when they finally (hopefully) rule together. To do that, he had to send his “Seschenal” away to prove he could rule on his own terms
What do you think?