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.
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.
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.