Hi Gryphon,
Don't read anything into having both a student interviewer and an admissions officer at your interview. I want to validate two facts:
1) All interviews are blind. Neither individual at your interview has seen your application or resume at all, as all interviews at Darden are blind. Therefore they would not have any opportunity to form an opinion about your candidacy prior to the interview.
2) All Student Admissions Committee members will conduct a few interviews with an admissions officer present. We were all trained to do interviews this year, and it is par for the course that a few interviews with have admissions officers present for OUR benefit. These are randomly assigned to candidates, so having two people at your interview, again, is no reflection of your candidacy.
Hope that helps! Glad you had a good visit to Darden, and good luck with the process!