During the fight in the gym Schillinger alternates between having on two punch mitts to only one and then back again.
After Beecher slits Metzgers throat, Beecher is shown cutting his nails. In the long shot, there is no blood visible on his hands, but in the close up, his hands are covered in blood, that would have been visible from either angle.
When Governor Devlin is holding a press conference to talk about the company taking over Oz's infirmary, Dr. Nathan appears suddenly among the others behind him in one brief shot, then disappears again. After Devlin is done talking, the camera immediately cuts to her, watching as if she's been in the crowd the entire time.