In recruitment, impartiality is not just an ethical issue. It can also be a legal matter. For example if an appointment is seen as unfair and a complaint is made, or conversely if a candidate is rejected and, for whatever reason, decides to pull the discrimination card. Therefore, it is important to observe and maintain consistent standards when interviewing and evaluating candidates at all times.
More information: http://recruitloop.com/blog/how-to-evaluate-candidates-consistently/