During the opening scene, Wojo says "Nick had the files all screwed up". This past-tense reference is the first story line indication that the Yemana character was no longer at the 12th Precinct. (Jack Soo had died in January 1979, a month before this episode's original air date.)
Barney asked Harris if he had notified the Treasury Department when it's actually the Secret Service that handles counterfeiting. At the time of broadcast, the Secret Service was part of the Treasury Department, since the assassination of US President Abraham Lincoln. In the Post 9/11 era it was incorporated into the Department of Homeland Security.