When threatening Kyle at the cliff, Detective Michener makes a reference to the Axis Berlin-Rome-Tokyo. Although individual treaties had been signed between the three countries, their military alliance did not receive that name until the signatures of the Pact of Steel and the Tripartite Pact in 1939 and 1940. The series is set in 1938.
Councilman Charlton Townsend refers to Richard Goss's SS bodyguard as his "flying monkey." The show is set in 1938, but the hit movie "The Wizard of Oz" came out in 1939. Granted, Townsend could have read the book or watched the 1925 version of the movie, but that would have been a very obscure reference in 1938.