Luke 23:22

And he said unto them the third time, Why, what evil hath this man done? I have found no cause of death in him: I will therefore chastise him and release him. But they were urgent with loud voices, asking that he might be crucified. And their voices prevailed.

Far from Luke's attempting to exonerate Pilate, he omitted a number of efforts on the part of the pagan governor to release Jesus. Here is a list of the efforts Pilate made to release the Lord:

PILATE'S EFFORTS TO AVOID CONDEMNING JESUS

1. He asked that the Jews take him and judge him according to their own law (John 18:31). 2. He announced a verdict of innocence (Luke 23:4). 3. He sent him to Herod. (Luke 23:5-10). 4. He announced Jesus' innocence had been confirmed by Herod also (Luke 23:13-15). 5. He twice offered to substitute a lighter punishment (chastisement) (Luke 23:16,22). 6. He offered a choice between Barabbas and Christ, hoping the people would choose Jesus to be released (Matthew 27:15ff). 7. He suggested that they take Jesus without legal process and crucify him (John 19:6), promising to "look the other way" if they did. 8. He even appealed to Jesus to perform some wonder, by implication, that would make it easy to release him (see in my Commentary on John under John 19:11). 9. He "sought the more" to release him (John 19:11).

In view of the above, there can be no justification for the notion that Luke in any manner colored his narrative to improve the image of Pilate. As a matter of fact, Pilate's image appears starkly ugly enough in the chapter before us.

And their voices prevailed ... Prevailed over what? Over a cowardly governor who, with an army at his back, allowed himself to be bullied by the evil priests. Pilate signed the death warrant of a man he had repeatedly declared to be innocent; and, if there is anything worse than this that a governor might be guilty of, it is surely unknown to this writer.