34 minutes in the officer cuts the front of the victims dress revealing polka dot panties, in the next two to three minutes the panties change color several times as well as her bra at the 36 minute mark.
At the police roadside checkpoint, you can clearly see when the cops are looking at the tires on Col. Williams' vehicle that he is driving a Jeep Grand Cherokee. The real Russell Williams drove a Nissan Pathfinder, and later in the movie (near the end of the interrogation), we hear the Jim Smyth character correctly reference the "Pathfinder tracks" in the field next to Jessica Lloyd's house.