The second season episodes take place in snowy and gray winter, but many transitional aerial shots show Northern Virginia and Washington D.C. in a season when the trees are green and full of leaves.
When Elizabeth is talking to Jared while carrying sticks in the woods, Jared has his one hand in his pocket and when the camera angle changes, he now is holding wood in that hand. This happens a couple times.
The ECHO disk lacks all classified markings. The disk should have a red jacket to visually identify it. It should also have labels marking it as TOP SECRET with it's code word and declassification information.
Each disc is stored in a safe described as an "E.M.P.-grade hardened safe," but the one being accessed uses an electronic lock. Safes designed to withstand ElectroMagnetic Pulses cannot have electronic mechanisms, as the EMP would knock out all their functioning -- especially for an unshielded touchpad lock exposed to the environment.
As the ECHO code is scrolled through, it is very clear that the code is part of a graphical flight simulator application, and not part of a stealthy airframe model analysis application. It has also been somewhat "gibberished."
The lock on the ECHO safe can't be used to to store classified material. This type of lock is not GSA approved.
The aerial shot of the Pentagon shows present day road configurations, 9/11 Memorial, Metrobus terminal, helipad and remote delivery facility, none of which existed in the early 1980s when the show takes place.
The Chevrolet pickup truck parked next to the cabin is equipped with clear-lens multi-reflector headlamps, which did not appear in on vehicles in the US until 1990.
The safe containing the ECHO disk has a modern digital combination lock. These were not available until the late 1990's.