You know who I am, but did not originally address me as Captain. As such you are either a higher-up or a fellow Captain in the defense force. Civilians may address me without title, but that is not common. Higher ups usually are more careful about addressing ranked officers, as well. So you're a fellow Captain as well as someone with enough disrespect to play a guessing game rather than reveal yourself.

[She'll pause for a moment to let him digest her findings. While Ashiro may have a guess on hand, she wants him to stew on this a bit longer before she comes out and says it.]