Non-Member Present at Applicant Interview

Our board received a request from a resident shareholder, who is not a member of our board, to be present at the interview for potential buyers of the apartment next to his. Apparently there have been "issues" between the neighbors. The shareholder's comment to us was, "Some boards allow this." Well, I don't care what "some" boards do, I think an interview is stressful enough for the applicants without bringing in a random shareholder to witness the interview. I'm not comfortable with this and I voted no on this request. I am, however, curious. I'm sure that somewhere there is a board that allows non members to be present at board interviews. Has anyone ever been involved in such a situation? If so, why did you allow it, and how did it work out?