It's honestly a sensible assumption, at this point. Not safe to rule out other possibilities, but...

"Dr. Tilly," he mumbles to himself, making a note. People using given names in impersonal contexts is fine, but if he wants to blend in with the rest of her patients, making anything odd as he makes the appointment wouldn't be helpful.

It feels a little repetitive, and unhelpful besides, but he answers: "I don't know. It's been slow, I noticed a few weeks ago, but it might have started... September? August? Maybe when the network started."