Someone that is cleared has to sign out the documents that they look at, and they have to return them when they are finished looking at them. This is done each day (and each time that you look at them) You may not even leave them on your desk when you go out to lunch. Theoretically, a document will be missed by the security officer on the day that the document is not returned. The security officer will know this when they close out their log for the day's activities.
The first question is why did Mr Berger have a need to know about these documents. The second question is if he did have a need to know did he have the appropriate clearances to read them. The third question is why didn't the security officer nail him on the afternoon of the first day when he tried to remove one. And the fourth question is why isn't he now in an appropriate slammer?
I certainly would like to know.