Revealing mistake: As the gang drives up to the space-ship diner, cars are whizzing by in the background. When they are driving to the base there's also a clip of a fire truck going down the highway in the distance.
Revealing mistake: During the opening credits, just before they discover the hotel, 10K fires a round from his rifle. This strikes a medallion hanging from Doc's neck and the bullet ricochets and kills a zombie. 10K ejects the spent cartridge from his bolt-action rifle. This cartridge spins in the air and lands on rocks; however, what lands is not a spent cartridge, but a live round, with bullet intact.
Answer: When the plant zombies would attack they would wrap people with the vines and hold them, so they couldn't escape.