When Linda and Chad are at the Russian Embassy the picture behind Linda and Chad on the office wall is Boris Yeltsin's portrait, then in security camera shot, showing Chad and Linda waiting for Krapotkin, the portrait is of Vladimir Putin.
When Linda and Chad are at the Russian Embassy, the video surveillance shot shows that it is May 1st, later it shows Harry looking at his cell phone with the date being 17/9/2008, September 17th, obviously 5 months later.
In the final scene with Linda, in which she's being picked up by the CIA, an agent pulls alongside her on the right. In the second shot depicting him, the car is in the same spot, in a traffic lane (not parked), but the shifter is in the Park position.
When Linda asks Ted to break into the Osbourne house, he puts his hands up while telling her "No, No" and no ring is visible. In the next shot, you so him making this gesture from another angle and there is clearing a wedding band on Ted's wedding finger.
On his 5.2 mile run, after crossing the Francis Scott Key Bridge, Harry runs north up a steep hill on 35th Street, and a black car passes him from behind. In reality, this street runs one-way in the opposite direction. Also, the car appears to continue straight through the intersection, but is then seen going east on Prospect Street; Harry watches it drive away while facing northwest, then turns and jogs away in the same direction the car went, passing the same tree that the car just passed.
At the end of the film, when the CIA supervisor opens & closes a file marked "Top Secret", the file's cover-sheet is outlined in red. This is an error because the cover-sheet of all "Top Secret" classified files are outlined in orange. Red is saved for the cover-sheets of all classified files marked "Secret" and blue is used for the cover-sheets of all classified files marked "Confidential".
Mr. Krapotkin asks, about the CD, "PC or Mac"? Most data CD formats are readable by either type of computer, however the character could be asking in case the data is in a format readable only on one type of machine, e.g. a word processor package that exists only for the Mac.
Katie reports that it's 5.2 miles on the odometer from the Cox residence on Olive St. NW to West Potomac Park just off the Lincoln Memorial. It's actually no more than about two miles. This may be deliberate however. Harry often lies to try to impress his dates. Perhaps he had Katie go the long away around to the park so he could take the shortcut back that his about two miles, but implying that it is 5 miles to Katie.
In the scene where Osbourne Cox receives his notice of insufficient funds, when he looks at the paper, it clearly says "We recently we received..." Clearly whoever typed up the paper was torn between using the word 'recently' or 'received', and, after deciding on one of them, forgot to remove the other.
The goof items below may give away important plot points.
When Osborne has Ted at gunpoint in his basement, his eyes fix at one point (presumably at Ted) as he speaks, while he is pointing the gun at a slightly different direction (outwards to his left hand side). Shooting the gun into that direction (as depicted), the bullet would have flown past Ted's right hand side instead of hitting him.
After the shooting, Harry picks his gun up in his right hand. As he stands up, he transfers it to his left hand. In the immediate reverse shot, he is still holding the gun in his right hand. Also, the position of his left hand (in a two-handed grip) changes between shots.