Nice, a detailed reply for a change.
This one and one other I mentioned quite a while back about people who were otherwise still "alive" just completely insane and over run with destructive impulses. That one and this one are the only valid routes to a zombie apocalypse that are actually possible. That's why I found the take interesting. Because it wasn't based on the "dead" coming back to life because that is fucking impossible, but some form of infection that made people act this way.