I think you’re reading too much into it. The caller concerned about his family member with MS sounded very genuine and his accent authentic (I’ve grown up in the south and live in a rural area on the coast of SC.

The “doctor” however I’m not so sure about. Odd accent on that one and his line of questioning unprofessional for someone in his profession. A plant? Maybe. Might be a good idea to start pre-screening the calls.