Visible crew/equipment: When Maggie is in the pharmacy looking for abortion pills and is attacked, the camera cuts to Glenn twice before he rips the shelf from the wall to save her. The first time, behind him you can see that the glass next to the storefront door is empty. In the second cut, you can see someone standing on the steps. It looks like Melissa McBride. (00:25:20 - 00:26:00)
The Walking Dead (2010)
1 visible crew/equipment mistake in Secrets - chronological order
Starring: Jon Bernthal, Sarah Wayne Callies, Steven Yeun, Andrew Lincoln
Genres: Horror
Continuity mistake: When Daryl is driving the hospital van, it shows that he is going to land upside down, on the vehicle's roof, when he drives off the parking garage. In the next scene, the vehicle lands on its wheels, as if it has done a complete front flip. (00:30:00)
Indifference - S4-E4
Trivia: When Michonne and Daryl are walking toward the gas station sign, above the word diesel it spells out HELL in upside down numbers. (00:08:59)
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