Continuity mistake: When the walkers come through the cars, most shots show Carl and Sophia to be under the same car. When Sophia is attacked by the walker, Carl is not there and Sophia is shown on her own in other shots as well. (00:19:25 - 00:20:05)
Suggested correction: They never get under the same car. When we see them first get under the cars, they are both seen getting under cars going in the same direction at the same time (they'd have to go in opposite direction to get under the same car from both sides). Then in the first close up of Sophia, we can see Carl's head in the shadow and then a strip of sunlight indicating 2 separate cars.
Pretty Much Dead Already - S2-E7
Revealing mistake: When Shane lets loose on the gang at the barn about the two walkers Hershel and Rick just brought out from the woods, he fires several shots into the female walker's torso, as he screams at Rick about them not being human. Then subsequently fires two shots at her head. Yet she is still moving when she should have dropped. As ANY blow to the brain kills instantly. But she doesn't drop until Shane dramatically moves right up to her and shoots her in the forehead.
Suggested correction: Those two shots were actually into the torso. He fired three into the torso, paused, two more into the heart and lungs, paused, then two more into the torso before he put one in the head.
Character mistake: While Hershel is sitting at the bar talking about what happened at the barn, he tells Rick what he was thinking about as he watched Rick run across the field, carrying Carl, who'd gotten shot. But it was Maggie who'd witnessed this through binoculars, and then yelled for Hershel.
Suggested correction: And he came outside to see Rick running across the field with Carl. No mistake.
