First of all, I know the interviewer, and he did this celebrity interview of Kathy Griffin absolutely wrong.
- Said he wasn't a fan (somewhat emphatically)
- Admitted to doing little or no research
- Proceeded to ignore his subject.
When I used to do celebrity interviews with the likes of Benicio del Toro, Ellen DeGeneres and various soap stars, I always did my research. In fact, doing your research can often make a tough subject putty in your hands. I know that my Benicio del Toro interview went longer than expected because he was surprised I knew so much about him (stalker!)
So keep these lessons in mind. I'm not suggesting that anyone lie about loving a celebrity's work, but a writer can be more diplomatic. And never tell a celebrity (or anyone) you didn't have the courtesy to research him or her. It only makes the writer and the publication look unprofessional.