Continuity mistake: In the scene where Merle is the in big box late 80's chevy with big 20-22 inch rims he is shown driving it in the barn yard drinking, playing music, and zombies following him. The shot changes a few times within the same scene with the big rims on, in one shot the car is shown with him driving it but the stock rims (15") are on the car, the paint of the car looks a little darker too. Then the shot changes again while he is still driving it and the big rims are on the chevy again. The shot that shows the stock rims is a pretty fast shot so it could be easy to miss.
Revealing mistake: Dale threatens to shoot Shane, and Shane walks right up to him until the barrel of Dale's rifle is against his chest. Just before Shane walks up to him, you can see the imprint of the rifle muzzle on Shane's shirt from an earlier take. (00:32:50)
Continuity mistake: When Rick, Carl, and Michonne are leaving King County (Rick's home), they must travel around a wreck involving two cars and an overturned RV. They drive along one side of the road. When the camera angle changes, they are on the opposite side of the road going the other way. (00:41:30)
Continuity mistake: When Glenn is with Tara and getting ready to move out, he puts on his helmet and you can see it is strapped on. When the shot changes, he swings the fence open and you can see his strap is lose. The camera angle changes again and the strap is back on again. (00:38:15)
Continuity mistake: When Beth is looking for a key in Officer Dawn's office, she encounters Joan lying dead in the office from bleeding out, apparently from suicide with a pair of surgical scissors. Her left hand is covered in blood. But when Officer Gorman enters the room and Joan starts to turn into a walker, the blood on her hand has disappeared.
Continuity mistake: At the crossroads, after Rick starts to walk away from Shane, Shane starts to tell the story of what happened with the outbreak. Rick pauses and is looking off to his right as he is in the blurry foreground with Shane talking behind him, looking towards the left of camera. The angle cuts to a view from behind Rick, and suddenly Rick has his head turned to his left now, but also towards the left of camera but from this angle. (00:16:43)
Continuity mistake: Merle is handcuffed to a pipe and tries to seduce Andrea, saying they are going to die anyways. When she says, she'd rather die, his hands are apart closer to his sides, then when it cuts to a close up of him, suddenly he's got his hands together with one finger pointed at the other hand. (00:16:33)