At the end of the show when Shane and T-Dog are burning the dead walkers, just as Shane throws his torch on to the pile to ignite it, to the right side of the pile is an obvious plastic head, that of a mannequin or crash test dummy, rather than a dead walker.
Sophia's body at the beginning is in a different position than the previous episode.
When Lori sees that she is about to hit a walker with the car she jerks the wheel to the right causing her to hit the walker with the front left (drivers side) side of the car. However, in the next frame you can see that windshield of her car is cracked on the right side (passenger side).
When Rick is talking with the guy behind the bar, his hand is on his hip near his pistol; in the reflection in the mirror, his hands are together in front of his crotch.
As Carol breaks free from Daryl after the barn massacre, Andrea turns her head and watches Carol over her shoulder. Moments later, Andrea is seen turning around and walking away from Dale's side. Moments after that, the same shot of Andrea looking over her shoulder at Carol is shown.
After Maggie slaps Shane, a boom microphone and a huge light reflector are briefly reflected in the Greenes' front door when she opens it.
When Shane presses Hershel as to how Sophia got in the barn, Hershel's response is that "maybe" Otis put her in there. This is not possible. Daryl discovered that Sophia had found shelter and just eaten long after Carl was shot. After the Carl incident, the whereabouts of Otis are always known.