Ducky states that each of the six vigilante murders were committed in different cities, yet the map he is using shows that two of the murders were both carried out in Buffalo, New York.
When presented with the Secretary of Defense's challenge coin Director Vance says "highest rank gets free drinks at the bar, there's only one coin higher than this." This is incorrect, there are actually two higher ranks than the Secretary of Defense in the U.S. government hierarchy, those being the Vice President and President of the United States.
The seal of the Superior Court, District of Columbia, seen on the building at the end, is incorrect. The seal should have crossed flags of the United States and the District of Columbia with the scales between them.
At the end you see Elly, Tores and McGee standing outside window of the building. You can clearly see camera and crew member in window reflection.
Gibbs' diner that he often frequents is shown on a map with an address in southeast DC. The address shown is actually in southwest DC and is in a residential area.