Now Caiaphas was he, which gave counsel to the Jews, that it was expedient that one man should die for the people. Caiaphas was he which gave counsel, etc. - Therefore he was an improper person to sit in judgment on Christ, whom he had prejudged and precondemned: see on John 11:50-52 (note). But Christ must not be treated according to the rules of justice: if he had, he could not have been put to death.
Related Commentaries of John 18:14
John 18:14
14 Now Caiaphas was he, which gave counsel to the Jews, that it was expedient that one man should die for the people.