If before, Sean admired Anya's personality and quick thinking... knowing when to advance and when to cut her losses... now, it kind of irritated him.
That saying, he knew she made the right call.
It was quite a terrifying situation to be in, when the person you thought you had been fooling and playing all around, suddenly flips the script on its head, and it turns out it was you being played.
More than that, the person was strong... Stronger than you even.
Sean's irritation was more from the fact that he didn't get what he wanted. Although he was already able to deduce who or what she meant by mist demon, he just wanted to ask her to confirm, and let her be on her way.
He did not have any intent on stifling her shine. In the original timeline of the book, she had risen to the top ten at the catastrophic end of the examination, emerging as a true dark horse.
