Zombie Road - S2-E3
Other mistake: When Doc and Wrecking Ball have to jump out of the car to escape the Z's, Doc jumps from the passenger seat, but then several seconds later, Wrecking Ball (who is driving) also jumps from the passenger seat. While it's possible he shifted over the seats, it's more likely that the crew member we now see driving the car was in the way. On top of this double-jump-out-the-same-side issue, is the fact they end up lying on the road just a few feet from each other, rather than what should be well over 100 feet apart (based on the speed of the car).
Answer: When the plant zombies would attack they would wrap people with the vines and hold them, so they couldn't escape.