It seems the rules are different when the guilty party is a police officer. Mario Chavez is a Prince George's County, Maryland police officer who was driving his patrol car at the time of the accident. For some reason the black box recording device for his police cruiser has not been checked for evidence due to "software problems." A page of nurse's notes about Chavez after his admission to Prince George's Hospital after the crash has also disappeared.
(Via The Agitator.)