Whenever I talked with an applicant about their job interviews, I always asked the applicant what the interviewer had said about next steps.  Based on this information, I could know whether the person had passed or failed an interview.

If the interviewer scheduled another interview before the applicant walked out the door, the applicant had a successful interview.

If interviewers summarized by saying they needed to compare notes before reaching a decision, the applicant very likely had an excellent interview.

If the interviewer told applicants that they were speaking with several applicants and would get back to the applicants in a few weeks, I knew that the applicants had very likely failed the interview.