The bearded man in the gun store that helps Bob is Stephen Hunter, the author of the book "Point of Impact" on which the series is based upon.
Release was delayed due to the publicized shooting of Dallas Police officers on July 8, 2016.
All of season ones episodes, except episode 3 "Musa Qala", are common military terms.
Season 3, episode 3, when Harris and Bob Lee go to interview Colby, Harris suggests that they try a "good-cop thing . . . Like, you know, Simon & Simon? Like, more like the younger Simon than the older Simon." The older Simon to which he is referring was played by Gerald McRaney who plays Red Bama, Sr. In this series.
In S1:Ep.6 (Killing Zone) Rathford O'Brien tells Bob Lee, "That's the way of the gun, pork". Ryan Phillipe starred alongside Benicio Del Toro in the movie "The Way of the Gun" (2000).