Factual error: Throughout the series, there are scenes of decapitated heads speaking with audible voices, in spite of the fact that they have no diaphragms, lungs or larynxes. Even if a decapitated head was somehow fully animate, it still couldn't utter a sound.
Factual error: In a scene when the group is supposed to be near the east coast a Banner furnace and fuel truck explode, the problem is, Banner Fuel is only in Spokane, WA, on the west coast. Spokane is where the show is filmed.
Factual error: When the group are heading to California after leaving the Missouri home of Lt. Warren they somehow end up in South Dakota. And go within 251 miles of Salt Lake City and then back track over the Rocky mountains to the facility in Fort Collins Colorado.
Factual error: At the beginning when the group is at the USA/Mexican border and Vasquez fires his last bullet and then tries to fire again the recoil of his gun is shown, despite being out of ammo. (00:02:20)
Answer: When the plant zombies would attack they would wrap people with the vines and hold them, so they couldn't escape.