The other thing to remember is that no single interviewer gets to decide who gets admitted. That decision is made in committee. One student’s interviewer may be, and often is, the biggest advocate for that student in presenting to the committee, but the other members of the committee also have their own interviewees they are pushing and also have votes.
You cannot read anything into the reactions of the interviewers, other than one person’s thoughts and style, which is more reflective of personality than anything else.