Once upon a time there was a Virginia agency that had recently moved to Active Directory. They used to have a forest of NT4 domains, but decided on a single enterprise admin model to reduce overhead. One day a central enterprise admin decided to write a script to remove user accounts, unfortunately when run in the production environment it emptied the entire statewide directory.

Lowly non-enterprise admins watched in horror across the state as the accounts disappeared. Since there were DCs located in each district the enterprise admins in their infinite wisdom had not done a schema backup. Lo and behold a few alert souls physically pulled the plug on their remote DC before said changes were fully propagated. This allowed Microsoft platinum support engineers to restore the user accounts.

The moral of the story is too much automation and too little testing are a recipe for disaster. But having people in the loop is just plain CYA.