Visible crew/equipment: Negan and Carl go for a ride in the big truck. Daryl tells Negan not to harm Carl and he flips him off. In this scene, the camera tracks upward and its shadow casts on the truck. Also a film light can be seen reflected in the door jam.
The Day Will Come When You Won't Be - S7-E1
Continuity mistake: When Negan makes Rick get the axe from the top of the RV, Rick is fighting the Walkers as he heads for the RV door after picking up the axe. He slams a walker's head into the back of the RV, blood splattering everywhere. Next scene shows Negan and Rick driving back to the group, and the back of the RV is spotless.
Continuity mistake: When they get back to the community after stealing all explosives from the road, the Saviors show up and search for Daryl. When they do, that's when they show a one-second clip of the guy Dwight killed a few episodes back, the guy who said there was nothing to go back to. The guy is then shown to be a walker in the defense yard of the Saviors. So, how is he shutting the van doors of a vehicle in this episode? (00:43:12)
Continuity mistake: When Morgan and Carol leave The Kingdom on horseback to take Carol to her "gone, not gone" house, Morgan is riding on Carol's right. When they are shown arriving, and Morgan dismounts, his horse is slightly in front of Carol's and to her left. Morgan throws down his staff and slings his reins over the picket fence. Then, he returns to help the still recovering Carol from her horse, and we see Morgan's horse is back standing neatly next to Carol's on her right. (00:42:13 - 00:42:52)
The Day Will Come When You Won't Be - S7-E1
Other mistake: When Rick is on top of the RV, Negan peppers the roof with bullets from the inside, so that Rick has to run and jump onto the hanging walker. Negan's using a machine gun, so a lot of bullets, and the exit holes that are made, are visible on the roof. The softer material of the inside ceiling would have been really torn up, but when Rick gets back into the RV with Negan's axe, the ceiling is undamaged. (00:21:38 - 00:24:36)
Hostiles and Calamities - S7-E11
Revealing mistake: When Frankie and Tanya visit Eugene while he's playing the video game, he refuses to give them the pills he made. They call him a coward then leave, and in the next closeup of Eugene's video game screen we can see his reflection, but the problem is his reflection is not reversed as it should be (note his shirt buttons, etc). (00:44:10)
Continuity mistake: When Rick and Aaron are loading up the supplies from the houseboat, they put a container with a red can in straight and flush with the other container, so that the lid sticking up is to the left. In the interior shot of the van, the container is twisted sideways and pushed back with the lid to the front.
The Day Will Come When You Won't Be - S7-E1
Revealing mistake: When they pick up Glenn's body, for a brief moment, you can see his head is fully intact.
Other mistake: When the Alexandria Group are at the Hilltop trying to convince Gregory to join them in their fight against the Saviors, we can see the actresses who play Michonne and Maggie trying to hold in their laughter. (00:06:02)
Factual error: Rosita picks up a spent cartridge fired from the desert eagle earlier in the episode, which is either a .357 Magnum, .44 Magnum, or .50 AE as those are the only chambers that the desert eagle is made in. She then asks Eugene to make her a bullet. In the following episode he does and she uses that bullet to fire a pot shot at Negan. But the casing that she picked up would not fit the 9mm Beretta she uses, nor could it be modified to do so.
Revealing mistake: When the two cars drive down the freeway with the cable in-between them, there is no blood or body parts on the cars at the end despite the carnage, suggesting CGI effects.
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.