futher proof of discrepancy: pharisees don't want defilement before passover meal during trial of jesus. it is clear in john that jesus was already under arrest before evening of passover meal.
John 18:28
King James Version (KJV)
28 Then led they Jesus from Caiaphas unto the hall of judgment: and it was early; and they themselves went not into the judgment hall, lest they should be defiled; but that they might eat the passover.