Does that imply a spy within Los Alamos?
No. It implies multiple spies and supporters.
SPIES. Lots of them. In most classified spaces the ID tags are color coded. My company uses green for TS, yellow for secret. Red is for escorted visitors. Red/white indicates a foreign visitor. Classified discussions are supposed to take place only in secured spaces where all the parties are known to be cleared for the specific project. During the reign of "BJ" Clinton, the color coded badge system was eliminated at Los Alamos. It made people "feel bad" because they were not all "equal". Bad move. It made it impossible for employees to know whether a foreign national was sitting within earshot of classified comments made in inappropriate locations like a cafeteria or break room.
There is a standard protocol for making classified visits to a site. The security departments exchange written confirmation of the visit, the names and clearance levels and the purpose of the visit. A specific time and place is is designated. Normally a SCIF (Secure Compartmented Information Facility) is allocated for the meeting. Any time classified information is accessed, the person who observes it is required to sign and date the folder containing the info. The use of removable media allows the drives to be stored in a safe when the cleared personnel are not using them. Unfortunately, it also opens the possibility for theft of volumes of classified information when the cleared personnel are not trustworthy and no secondary physical search is enforced to detect the problem.