I believe that both parties are using kenjougo/sonkeigo when speaking with each other. (I'm guessing that this is because one is a customer - thus deserving of respect - and the other is a doctor - also deserving of respect?)
I guess I was assuming that both parties in the conversation come to a similar ranking in this situation...but this story would indicate that this is not always the case.
Am I understanding this correctly? And if so, is this a relatively normal occurrence?
(added image per member request. Please excuse my ugly (and possibly incorrect) study notes.)