In 1982, Richard B. Russell went through the Panama Canal and arrived at Mare Island Naval Shipyard in Vallejo, California, for an extended overhaul. During her time at Mare Island, it was decided that she would become a special projects submarine. After a short period of post-overhaul testing and sea trials, she underwent extensive ocean engineering modifications prior to commencing operations as a unit of Submarine Development Group 1. As a member of Sub Dev Group 1, she spearheaded a testing program for submarine rescue technology.
So the sub was retrofitted for sub rescue, and reading into that, designed to enable divers to exit and enter the sub while submerged. This would be an asset for a clandestine operation. This is where your rogue sub idea comes into play. Did the sub get scrapped in 2003 as they claim, or is it in operation by the C_A?