The doctor's identity remains ambiguous in all aspects - they simply will not give a name, even if directly asked, but away from Guard members they will share more about their craft out of appreciation for the interest. Garrus will get the impression that they are very knowledgeable about potions of various sorts. It also seems that Passei is not the only client of theirs, although they will not tell stories about any others. Meanwhile: the other group members might, when Passei notices the doctor and Garrus moving away from the group, catch her talking about how she has to remember to get her medication from the doctor before bed. She will not elaborate on this, brushing off any questions kind of sheepishly and saying she doesn't want to worry anyone, it's just a condition that developed recently and isn't contagious.

The doctor, if asked again later about this by Garrus, will staunchly refuse to divulge the purpose or nature of this medication. However, they do not seem to be doing so out of any concern for Passei's privacy... overall, it looks like the doctor's primary interest is the continuation of their practice; they don't give off a feeling of liking or disliking their employer.