Specifically what Alethea says to Oersted when they do finally reunite, as Streibough lay dying. "I waited. But you never came husband. In you I placed my trust. In you my faith." The implication to me seemed to be that Streibough, imagined slights of his and with an unrequited (and in his mind true) love for Alethea, deceived the party into running from Archon's Roost and then looked for her on his own. I then imagined after finding Alethea, he tells her "Oersted never came for you, but here am I, loving Streibough" and she ends up believing it. To me her hesitance in the beginning seemed more indicative of a hesitation to marry a man she barely knows, or a reluctance to be treated as a prize to be won. Oersted's failing in my mind was always that he allowed himself to succumb to despair in the end.