JFK Declassified: Tracking Oswald

In the first episode Baer makes a big deal out of LBJ's 11/23/63 conversation with Hoover where he asks "Have you established any more about the visit to the Soviet embassy in Mexico in September?" Baer compares Oswald's visit to the Soviet Embassy to some modern day terrorist visiting ISIS headquarters. However on the LBJ Hoover transcript, Baer blacks out Hoover's response: "No, that's one angle that's very confusing, for this reason – we have up here the tape and the photograph of the man who was at the Soviet embassy, using Oswald's name. That picture and the tape do not correspond to this man's voice, nor to his appearance. In other words, it appears that there is a second person who was at the Soviet embassy down there." In other words, Baer knows that Oswald was impersonated in Mexico City, but hides that from the viewer. I guess it's true that no one ever really retires from the CIA.