Other mistake: In Woodbury, on the street, while Andrea talks to the Governor, we can see everybody wearing jackets and orange, red and yellow trees, showing that the scene was shot during fall. According to the beginning of the third season, they had just passed through a hard winter. So it should be spring or the beginning of summer.
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.
Factual error: When Rick has given Andrea his revolver to end her life, he leaves the room with the others to leave Andrea and Michonne alone. The next thing you see is Rick, Tyrese and Daryl waiting outside the room. You hear the gun go off and then you hear a tinkle as a shell casing hits the floor (noticeably "lighter" than the sound the revolver would make when dropped). Revolvers do not eject a shell casing.
Other mistake: When Martinez shoots the grenade launcher for a second time the cross hairs are on the concrete wall of the guard tower yet the explosion does nothing to the concrete and destroys the top of The Tower.
Continuity mistake: When Andrea is attempting to retrieve the pliers on the floor she picks them up between her toes with the head facing up. In the next show the pliers can be seen with the head facing down when she grabs them with her hand.
30 Days Without an Accident - S4-E1
Continuity mistake: After Michonne gives Rick the shaver, he has his gloves in his right hand and the shaver in the left. As he walks up to the prison, he throws the shaver away on the ground. He continues up to where Carl is brushing the horse, still with his gloves in his right hand and left hand empty. He remains like this whilst talking to Carl, but as he pats the horse, then walks away, he has the shaver in his right hand and the gloves in his back right pocket. (00:11:44 - 00:12:14)
Visible crew/equipment: Visible crew behind the tree towards which Carl walks back after replying to Hershel's "it was so peaceful" comment. (00:22:20)
Indifference - S4-E4
Visible crew/equipment: During the scene where Daryl's group finds the auto shop, Daryl spits on his hand to wipe the window and is surprised by a zombie banging up against the window. He says, "Got some friends inside" and walks away. The camera pans to the window and a crew member wearing a white hat and (what appears to be) an orange shirt is visible in the reflection. He seems to be taking a picture (probably for continuity, which is pretty ironic). (00:09:50 - 00:33:05)
Internment - S4-E5
Continuity mistake: When Rick gets out of his car and talks to Maggie inside the prison gates. The car door opens and shuts throughout the conversation.
Internment - S4-E5
Continuity mistake: In the previous episode, Rick and Carol are shown hunting through houses for household drugs to fight the flu. They even make a mention that most of what they find expired a year ago, but to bring it back to Hershel anyway, and let him decide about it. But in this episode, Rick returns, talks to Hershel, and no mention is made about him bringing medicine. Considering how important it was to fight the flu with any means possible, Rick would not have let Carol drive off with the potentially life-saving drugs.
Too Far Gone - S4-E8
Continuity mistake: When the Governor and his group show up and bomb one of the guard towers to get Rick and his group's attention, when Rick first runs outside the guard tower on the far left is on fire, but when Rick walks down to the fence to talk to the Governor the guard tower in front by the front gate is the one on fire. And it switches back and forth between the two. (00:16:05 - 00:19:15)
Too Far Gone - S4-E8
Factual error: When Lilly comes across the Governor's body, she points her 1911 at him. In one shot, we see her from behind with the hammer forward on her 1911. In the next shot she immediately kills the Governor by shooting him. A 1911 will not fire unless the hammer is back. (00:49:00 - 00:50:00)
Too Far Gone - S4-E8
Continuity mistake: When Hershel crawls away and the fight begins, in the long shots of the governor's men Hershel's body can not be seen next to the cars, this is from all angles.
Too Far Gone - S4-E8
Continuity mistake: After The Governor shows up at the prison with his arsenal, Hershel and Michonne are taken out of the vehicles and placed kneeling on the grass side by side, about 1 arm's length apart from each other. But when Rick makes his way down to the fence to talk with The Governor, Hershel and Michonne are now about 4 arms' lengths away from each other. This goes back and forth for a few shots.
Continuity mistake: The message in chalk Carl writes on the door changes from what we see him do. For example, he writes something on the middle part of the door (which doesn't look like the word "shoe") and then doesn't write on the inset part of the door below that. When we see the message, the inset part now has some writing on it.
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 Glenn wakes up in the prison you can see two chairs leaning against the walls behind him when he stands up. These are still present in the second shot, but when the camera moves back for the third shot they have mysteriously disappeared.
Character mistake: At the very end of the episode Tara tells Glenn that her sister and nephew were not supposed to be there. Tara had a niece not a nephew.
Continuity mistake: When Glenn wakes up we see the door behind him is flush with the concrete, but when he goes inside you see stairs he had to descend to get to the door. There is also no scene in the entire prison episodes where an outer orange door is preceded by steps, they are all flush. Also If you look at the door behind him you see two folding chairs leaning up against the door. When he turns to open the door the chairs are gone.
Continuity mistake: When Carl and Michonne are eating breakfast, and she is rolling up the sleeves to her new white shirt, it is untied. When the scene cuts to her sitting down the shirt is tied at the back. (00:03:20)
Answer: Walkers are attracted to noise, they can tell who's dead and who isn't dead, in S1 when Rick and Glenn cover themselves in walkers' guts they're able to get far by walking through the herd of walkers because they smell like they're dead, but as soon as the guts get washed off by the rain the walkers immediately attack them, if you draw attention to yourself they will attack you which we've seen that many times throughout the series that it's not always successful. Whether you're covered in guts hiding under dead corpses or under a car.