Right off the bat -- it's a fucking chat UI. I don't care that...
"Specialist physicians evaluated both the conversational quality as well as the responses to the post-questionnaire for scenarios within their domain expertise."
It is actually impossible to have a bedside manner over a chat interface, because a bedside manner is necessarily corporeal. The authors don't make that claim, so that's on Nature for running straight-up ad copy for Google's doctor-replacing product.