That does not pass the smell test.
I know people who have worked in secure defense installations. The tower unit of their computer was encased in a chicken wire cage that prevents you from inserting any type of removable media.
That computer is infrastructure. Somebody needed to load that computer with OS and applications and make sure it was connected to the network properly with proper privileges, etc. That somebody would have been an infrastructure specialist, like Ed Snowden.
The FBI and NSA agents looking for him should have noted him on a flight out of Hawaii real quick. If he flew direct to HK then it should have been even easier.
I’m surprised that NSA does not have a alert when any employee is traveling outside the US. I know people who have worked such jobs and they all had to notify their agency that they were planning a trip outside the US.