The king didn't understand Yale's reasons to fake his identity as a weak kid, but he didn't plan to ask. As for the Mysterious Expert that he had met before, he felt that it was an incarnation sent by Yale himself or some subordinate of him.
The king didn't plan to seek the truth about that matter. He knew that the master of Anpaes wasn't someone who acted with altruism, so he didn't complain about not being helped before. However, the king also knew that the master of Anpaes was scary when others messed with him.
The king didn't know what the true relationship between Yale and Aiwai was, but he knew that Aiwai was in the palace and it would be easy for her to be implicated. In his eyes, his eldest son together with his lackeys were all thoroughly dead if they dare to touch someone valued by Yale.