Elhame

What red flags, did you see how the doc behave himself with Tharn, what he said to confort him, Tharn doesn't see any red flag because there aren't for now. The doc took care of him way before Phaya came into the picture. Plus if I think about it, Wansart must have felt bad betraying her/his clan by falling in love with Garuda so I think there still is this guilt inside Tharn. He probably thinks he is the cause of a new war and Garuda's death. Thats why he is more closed of than Phaya about his feelings, people are unfair with Tharn. Sacrifying himself for Phaya every time shows that his love is as great as Phaya's. But ok everyone has his point of view.
And I believe that even when Tharn will discover the doc's true identity, he will not hate him, there're from the same clan and he feels guilty about everything.
SORRY!!! it's quite long but I wanted to share my view.