I love your description of your friend's technique for taking a history. It goes against everything we're taught about taking a history in med school. But I know it's bound to work except for some of the very compulsive patients.
Those are the ones who have to tell their story from beginning to the end and any distraction or question means we start over. I eventually figure them out, let them finish and try a version of your friend's 20 questions.
And I imagine them frustrating the dickens out of every other doc they ever saw.
In my business, one of my great joys were those occasions when one of my frustrating clients would announce that he was leaving me for another practitioner who I knew to be precisely the individual he deserved to be with. A guilty pleasure, I know, but damn near irresistable.