
Why ?
He’s a head spy, he teaches her that over confidence can cost lifes - he warns her several times and still gives her a way out
He’s not a white knight, he won’t save her, but instead he considered her ambition : she wants to become a high. Ranking official to serve the king
So far he just showed her how reckless she’s been
He certainly measured her for his own benefits , but he also went on to explain and let her take responsibilities
It’s not too often that a man gives that much respect to a woman : she underestimated him and the risks, she’s overconfident, so failed, but he didn’t rebuke her like Chloe and send her back home - that gives her an opportunity to grow

Even if all that is true, who would fall so easily for someone who saw their humiliation or was a direct cause of it. From the spoilers I saw she does go on to try and keep her distance, because it would only be natural for her to be wary of him. I made the comment because I see it way too often where an ml humiliates the fl (whether warranted or not) and it's completely waived later because she falls for him.
Her reaction to wanting to keep her distance is fairly normal (also, because he's dangerous.) She obviously can't fall for him from a distance (well she could but that wouldn't be a satisfying romance story) and he's going to be treating her like a pawn for a while, not a romantic interest, so if she just falls for him and gives in easily in that situation, I would be disappointed. It's like someone treats you as a tool and you fall for them, then they fall for you and the fact that you were treated as a tool is never addressed.
Honestly, after this (ch14-15) if she falls for him first or gives into him way too easily I'm gonna be so disappointed.