When Tyreese is about to kill Donna before she turns, you see Noah standing in the background and Allen walks over to him to give him a hug. The camera cuts to a close up on Tyreese and you can see Allen walk over and hug Ben again.
Before Michonne is waiting for the Governor all the lights in the room are off. After she hears a noise and kicks in the door to the Governors secret room all the lights in the room are suddenly on. It's hard to believe that she would pause first to do this, given the situation.
When the Governor addresses the townspeople, the Steadicam's shadow is briefly visible on the Governor's shirt, as the camera passes between him and the rigged floodlights.
At about 38:08 in or 5:08 remaining, after Michonne reemerges after the escape, someone feeding Michonne the line "You need me" can be heard.
Crew member seen after Michonne and the Governors fight, when Andrea is picking him up and off the floor.
When Tyreese's group is attacked by walkers in the woods Donna is screaming her head off, which just attracts more walkers. At this point it has been a good year since the fall, those that have survived this long would not be screaming like a frightened child every time they saw a walker, those that couldn't learn to break that habit would have died long ago. In fact had she been quiet and her screaming had not attracted even more walkers she might not have gotten bitten.
No way that Michone, who is uber-vigilant and suspicious would unchain Penny before removing the hood hiding her face.