I would take the interview over social event any day unless program director is actually present. Many programs don't keep tabs on the students during social events, and since there are so many students, that even if you are present, some residents don't remember you the next day during the interview.
From my experience, residents have little say in who gets in unless they are the chief/senior residents who are actually interviewing you.
Since you rotated, I don't think it matters.