When Commander Fischer is talking to Voight and Erin about Bunny not getting the reward money, he turns away from them and walks down the corridor after telling them they did a good job. However, the next camera shot (which is focused on Voight) clearly shows Commander Fischer's left arm and shoulder as if he was still standing there facing them.
Olinsky's knit hat is black when he & Ruzek find the wrecked fence, then a brownish-burgundy color when the truck is pulled out of the water, and black again when they do the notification.
When they cuff the killer in the alley his hands are behind his back. When he gets out of the police car he's cuffed in front.