Continuity mistake: As the group kills the walkers that come out of the barn, the camera shows several different vantage points from in front of the barn, inside of the barn etc., it shows the walkers lying with a clear path between them, and in another it shows the walkers lying in a jumbled pile with no path between them. This goes back and forth a few times until Sophia comes out of the barn, and there is no clear path again.
Continuity mistake: As Daryl and Shane argue near the start, Daryl's movements don't correspond with the changing shots: one moment he is standing in front of Carol, then he is standing by her, then he has moved closer to Rick - all within the same one-liners. As his argument with Shane grows, he again is standing by Carol, or closer, near Rick. At one point, a shot shows Daryl about to lounge at Shane, as Rick blocks him, but the very next shot shows him right next to Carol, who at that point would have been standing behind Rick. (00:10:00 - 00:11:00)
Continuity mistake: After Carol tells Shane they are not leaving without finding Sophia, Daryl enters and reminds Shane about the doll he found down at the swamp earlier, and they start to argue. During this he crosses front to Carol's right. In the very next shot Daryl is suddenly shown standing in the same spot as prior, next to Carol. (00:10:00)oprlvr33
Continuity mistake: Deleted footage/special release only: Carol confronts Daryl about the boy being held hostage inside the barn (following Sophia's death), reasoning with him about pretending not to care when he truly does. At one point he moves to her, almost in her face. However, the following shot shows only a close up of Carol, implying they are standing feet apart, which is not the case. (00:24:10)oprlvr33
Other mistake: As Daryl carries a saddle toward the barn, in the far shot, there is no one around. The shot then changes to him entering the barn carrying the saddle inside. Suddenly we now see Carol coming around the corner, several yards behind him. Where did she come from? Unless she was already inside next door and saw him enter, she shouldn't have been there.