The royal commander wasn't just stunned, he had to control his urge to ask or say Alora anything about her actions. Instead of bothering about the consequences, he wanted to follow her command due to the suspicious actions of Agost. So he bowed to her in acceptance and departed swiftly.
Arihan finally questioned her when they were left alone in the study room, "Why are you doing this, Princess Alora?"
She doesn't have the right to capture the prince of another kingdom. She needs approval from the Crown Princess or Queen. Not to mention, Agost has a crescent mark, the people of Anka and nobles could go against the royals.
Alora turned to Arihan. She could read the confusion in his eyes. When he had a few questions due to her actions, she had many questions, too, but he wasn't answering her. He didn't answer her and he didn't seem to answer her even if she questioned the past. Thus she went by her intuition, her gut feeling to solve the crisis.