All the info is now digitized and stored on servers. The is a small, select group of people who administer access privileges to the various (10's of thousands) servers which hold the information.
If you're one of those who admin that access system, you can give yourself access to anything.
However, these folks have the HIGHEST TS/Crypto/Specat/Limdis clearances available...and in the OLD days went through a Special Background Investigation...and lie detectors before getting such clearance.
They better question is: How did this guy slip through the system...even with lie detectors?
What it boils down to is why would a grunt have bulk access as opposed to one-record-at-a-time which can be audited?
Is there a mysterious lover in the shadows? Someone unhappy with current DADT military policy?