That is Piso's justice. Verbally right, but morally wrong. Seneca tells us that Piso condemned a man on circumstancial evidence for murder; but when the suspect was at the place of execution, the man supposed to have been murdered exclaimed, “Hold, hold! I am the man supposed to have been killed.” The centurion sent back the prisoner to Piso, and explained the case to him; whereupon Piso condemned all three to death, saying, “Fiat justitia.” The man condemned is to be executed because sentence of death has been passed upon him, and fiat justitia; the centurion is to be executed because he has disobeyed orders, and fiat justitia; the man supposed to have been murdered is to be executed because he has been the cause of death to two innocent men, and fiat justitia etsi coelum ruat.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894