Handheld satellite phones the size of a Palm were not sold until the mid 1990s. Systems before that needed a antenna bigger than the one on handhelds. The tracking from airplane is right but they are tracking early analogue cell phones.
In La Catedral the arcade game Area 51 is present. Area 51 was released in 1995, Escobar died in 1993.
Murphy and Pena aren't assigned to Colombia until 1988, yet the series has them there at the beginning when Escobar began in the early 1980's.
Throughout most of Season 2 both the Narcos, Colombian military and paramilitary groups are seen armed with the Galil ACE an Israeli assault rifle which began manufacture in 2008. The series is set in the 1980s.
In several of the airport cut scenes showing aircraft taxiing, the aircraft shown are a Boeing 737-800 and a Boeing 767-300ER. Both these aircraft have winglets on the end of their wings. The first flight of a Boeing 737 model that was fitted with winglets happened in November 2002. The first Boeing 767 model that flew with winglets didn't happen until 2009. In another scene, an Airbus A340 is seen landing. This aircraft first flew in 1991.
A scene showing the Port of Miami shows mountains in the background. The area in and around Miami is flat with no mountains.
Major Wysession is actually a Colonel. Early on in the season, his eagle rank insignia is properly adhered to his uniform shirt collar. Later on, it is woefully misplaced, in two ways. A United States Marine Colonel would never have his rank insignia, or any other medals improperly placed on his uniform.
The name of Colombia's most famous writer, Garcia Marquez, is mispronounced by the character Steve Murphy who mistakenly says "Mar QUEZ" instead of "MAR quez," and mispronounces "Cartajena" with an "enyay" instead of an "en."