Mr X introduces a brand new requirement NOT in the Selection Criteria

You have diligently and enthusiastically applied, passed the recruiter's interview with flying colours and made the short list. Hurrah. Flown interstate, you're now in the interview chamber. Mr X introduces a brand new requirement NOT stated or implied in the Selection Criteria. Holy Toledo! If you knew that, you would never have applied. You object to the Chairman, asking him to rule that out. He allows his friend's requirement to stand. You fail automatically. Change this practice please. Simple honest advice beforehand would do the trick. Not arrogance.