The Sword of the South

I've been re-reading the snippet that David posted on The Wizard wars and I'd like more info on when he said that the scrying spells were "hacked" I've worked on writing programs myself and on something that important,having one person that only has the authority to do so,with no-one checking up on the changes that have been made and no regular testing seems like a huge security hole. Especially without a backup somewhere just in case anything goes wrong. Just how they managed to pull off that feat is something I'd really like more info on.