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: The walkers could have knocked them down more than once. There may have been another wave that knocked down the fence earlier and they're going to put it up again soon.
Captain Defenestrator