Revealing mistake: At the end of the episode when Grissom and Archie are listening to the tape from Nick's kidnapping, the screen shows the audio being played. While the audio obviously changes, the lines that sketch what the sound would "look" like don't. In order for the sounds to be different, the lines would have to change too.
A Bullet Runs Through It (Part 2) - S6-E8
Revealing mistake: When the dead Cirque de Soleil investor guy (the one that bled out in Super Dave's body bags) is on the exam table, you can see him breathe twice, despite that his stomach and ribs are cut way open for Doc Robbins autopsy.
Still Life - S6-E10
Revealing mistake: The corpse's eyelids move/blink when the coroner slams the door in the morgue on the season finale of CSI.