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)
Other mistake: Doc is walking through a field listening to the radio. In the sky, center of the screen, an airplane is seen for about 8 seconds.
The Siege of Murphytown - S3-E12
Continuity mistake: Towards the end a woman is walking towards the fence completely covered in blood and guts, we see close ups of her boots, trousers and hands all covered in dripping blood. In the next shot she is still walking but her boots and trousers are clean and the blood on her hands is very dry.
Answer: When the plant zombies would attack they would wrap people with the vines and hold them, so they couldn't escape.