Sure it is. Someone decides to rape your nieghbor's wife, and you volunteer to knock at her door -- because she knows you and she'll open the door for you? How Kind! Yet by that kindness you become a rapist too. A completely culpable accomplice.
Another thing: suppose you find in your mailbox one day the title to a car you never bought or otherwise acquired, but you know the whereabouts of the vehicle and a key. If you take the car, but never legitimately acquired, you are committing theft despite existence of the state-issued title in your hand. If you know that the title was issued in error, it does not confer ownership.
Michael knows Greer's findings are predicated upon lies. If this could be proven in a criminal case, the fact that Greer accepted those lies would not protect Michael.