Newspapers have "fact checkers." Who validates your content?

Say an SME says that there are 7 items in the Configuration menu. Who checks to make sure it is not 8? When the policy is "within 90 days after receiving a widget, it must be tested" who looks to see that by the time the class is deployed, the materials reflect the new rule of 30 days? Who checks URLs to ensure that they actually point to the the described content?

Clearly the initial SME should not do this, so who does it in your organization? Do you do it differently when you revise content? Does everyone share a wiki that is supposed to be up-to-date?

John,

I work for a small private company (800 employees) and we have cooperation of the Technical Services and Engineering personnel to check our content. Items such as URLs are checked by Engineering and the instructors to verify validity. We ask Tech Services to verify content for accuracy and to ensure materials are complete.
As far as changing rules the company is ISO certified and all changes to ISO procedures are emailed to the instructors so that we know what times and content are current.