A reply I wrote on another comment, with some stuff I though of after this comment:
"I think there are bigger powers at play here. There was some suspicion going around that the church was embezzling funds in order to build a private army. Plus Shuri mentioned that a civil war was on it's way, that she intervened in the Christmas budget situation to delay that. But the Cardinal didn't like that, right?
Also the Cardinal and the Crown Prince don't get along at all. And the stupid Prince keeps talking about how much he likes Shuri in front of him. He even told him about his plans to take Shuri to the royal library! This would be a good opportunity to make the Prince, who keeps using his status to subdue the Cardinal, realize his own powerlessness.
And isn't it weird that there was a priest conveniently placed to help Jeremy get to the library? Plus he even told Jeremy to rush so that he could 'protect' Shuri. Which probably influenced Jeremy's judgement of what was happening. And if that area of the palace was completely empty, no guard in sight to help Jeremy while he was lost, how come they all got there so fast? And ready to arrest Jeremy to!
Plus I think the Cardinal was rather pleased with this situation. And he might be faking his surprise as well. That blond guy seemed to believe that the Church is good and that they are really committed to helping the commoners against the 'evil' nobles."
Guys, I don't think this is the Crown Prince's doing. He wouldn't gain anything from this. My money is on the creepy Cardinal. I'll explain:
What the Crown Prince wants is Shuri's love. And the only way I can see him getting closer to her in this situation is if he solved the problem himself. But he clearly can't, otherwise he would already done it.
The other possible suspects are the Queen and that creepy Cardinal. The Queen seems to dislike Shuri because she looks like the King's first wife, the Crown Prince's mother. And that Cardinal seems to dislike her for her help with the Christmas budget (and maybe more - I read some really disturbing theories).
The Cardinal is a more likely culprit because:
1. A priest was conveniently there to show Jeremy the way.
2. The Crown Prince mentioned to the Cardinal that he was planning to take Shuri to the royal library
3. He looked way too happy with the news that Jeremy was in jail and that he would get the chance to make Shuri's life harder.
4. The Cardinal and the Crown Prince clearly don't get along and it's a good opportunity to rub the Crown Prince's own powerlessness in his face.