Regardless of the occupation, almost everyone has encountered difficult people in the office. As someone employed in an industry that cares for both the body and mind, communicate to the interviewer that you're open to reaching out to that person. Maybe they have a legitimate reason for their negativity. Perhaps they're going through a difficult time. If the person is willing, then it's not a problem for you to lend an ear. If not, then it's no big deal. You know how to set boundaries in a professional setting, and as long as the person's attitude doesn't affect your performance, it's not an issue for you.