Hearing Eren's words made Sage Zavir realize something.
Zavir realized that this was not the same Eren he had faced during the Lazarus Project. He had different circumstances a few months ago when he was resurrecting Eliza.
At that time, Eren didn't run away from a siege because he was forced by his circumstances, making him stay on the battlefield despite being surrounded by myriad dangers both inside and outside the Birdcage Barrier.
However, Eren was not bound by the same restraints he had back then. The man did not believe in the Rankers' Code of Conduct to begin with. He was fine with saving his life even if it came at the cost of his reputation getting sullied.