When Tara is outside Minnow's house, the top two names in the row of doorbells are Clemens and Fennell, the show's producers.
When Tara arrives at the outside door of Minnow's apartment, the entry-phone keypad shows two of his neighbors as being 'Fennell' and 'Clemens' - an obvious inside-joke about the names of the show's co-producers.
The helicopter seen (G-AVCA) is a 1967 Brantly B-2B C/N (construction number) 466. Despite the British sounding name these were manufactured in Coppell, Texas. The Brantley helicopters were lovingly referred to as the "ice cream cone" because of their unique conical shaped fuselage.
Christopher Lee plays a military officer interrogating prisoners on the series, just as he had done as part of RAF intelligence in WW2.