When trying to identify the unknown sniper, Eliot tells Hardison to search the US Navy SEAL, Enlisted Database 91-95. They find the guy there but he's wearing a US Army uniform. He wasn't a SEAL and wouldn't be in the database searched.
When Hardison sends an SOS by using Vance's car headlights, he did 3 long 3 short 3 long, but SOS is actually 3 short 3 long 3 short ...---...
The signs in the subway station are marked "DC Subway". The subway system in the Washington, D.C., region is called Metro, and its logo is a black rectangle with a white 'M' and the word "metro" in lower case. The actual Metro's stations and trains look entirely different than what is depicted here.