You're two paygrades off. The article identifies Maziarz as a Gunnery Sergeant not a Master Gunnery Sergeant.
The people whom Maziarz described as his accomplices include:
Larry Richards, a Marine reserve colonel and detective with the Los Angeles County Sheriff's Department. He co-founded the Los Angeles Terrorism Early Warning Group in 1996. On the military side, he has received a Bronze Star for developing psychological-warfare strategies during the Iraq war.
David Litaker, an officer with the Los Angeles Police Department and, until recently, a Marine reserve colonel.
Mark Lowe, another Marine reserve officer and a pilot for Delta Air Lines.
Lauren Martin, a Navy reservist who worked as a civilian intelligence analyst at U.S. Northern Command headquarters at Peterson Air Force Base in Colorado.
In other words everyone else in this “spy” ring would have had the necessary clearances but not the “access” and the “need to know”.
They used him to gain access and decided they had the need to know because of their law enforcement responsibilities to the community.
Personally I am torn on this issue, perhaps because everyone involved knew what they were getting into and still decided that they had to do it for the sake of perhaps millions of Americans. On the other hand if such information was viewed by the wrong people it could aid in an attack that could kill millions as well.
There in lies the reasons why we have such qualifiers as access, need to know, and clearance, so those that don’t have all three don’t get to see secrets we don’t want exposed unnecessarily.