When Mary is shown waking up in the basement after first being abducted the sweat stain on her shirt changes size and color as the camera angle changes from close up to distance.
When discussing the carnage wrought by "Spanky" in New Jersey, Marshall refers to a missing witness but Chuck was never entered into WITSEC before being abducted and later killed.
As Stan, Marshall, and Dershowitz are leaving the office and watch the television with the news, some crew members can be seen in the reflection of the glass behind the television. Most noticeable is the director in white shorts and a white cap.