Neuvillette obeyed and follow the laws. Loyal to his archon and you but this time he have to choose between you or the law. And he chose the law. He didn't know your crime back then, he thought you're just an innocent citizen. He felt betrayed after finding out your true identity. As the hydro dragon, his emotions related to the Fontaine weather. Now it's raining hard due his sadness and dissappointment. Now he debating himself should he apologize that he can't help or resent you.