The infectious disease ward guy tells him "you may be a medical student, but because you do not have years of clinical experience and this isn't on your shortlist of specialties, and also because you are delirious with fever, I do not respect your opinion", and that's about the last thing Ned remembers before he loses hold of not only the conversation but also whatever treatment idea he'd been venturing. Maybe he'd just been asking for water and the doctor extrapolated the part about this having anything to do with being a medical student.