When Aaron and Tom are talking at the party, Tom claims that he would never pretend to know more than he really did. A few moments later Aaron shows him up as a fraud when he asks if Tom can name all the members of the President's cabinet. When Tom claims to know all the names, Aaron asks him "All twelve?". When Tom answers yes, Aaron delivers the 'gotcha' comeback "There's only ten." In fact there were 13 cabinet secretaries at the time the movie was made (the secretaries of State, Treasury, Defense, Interior, Agriculture, Commerce, Labor, Health & Human Services, Housing & Urban Development, Transportation, Energy, and Education, and the Attorney General). Since the film's release, two more secretaries have been added (Veteran's Affairs and Homeland Security).
When Jane tells Tom she can't go out with him because she is going to South America in a few days and needs to cram, she isn't going to South America. She's going to Nicaragua, which is in Central America.Jane takes such pride in being precise with her language, and in her intelligence that there is no way she would mix up Central and South America.
When Jane is giving the cab driver direction to the bar to meet her co-workers after the special report, the directions make no sense. She says "Capp's Bar" is on 17th & Vermont. There is no 17th & Vermont, the two streets do not intersect. Also Jane says "take Connecticut over to 15th and then straight down Vermont and we should bypass Thomas Circle". Connecticut and 15th do not intersect and going straight down Vermont will take you right through Thomas Circle, not around it.
Although it's not made clear, among the last scenes of the movie is Tom on a mobile lounge, which takes on passengers at the terminal and then lowers to travel. Tom's lounge moves away from the camera without first lowering. These mobile lounges, once a notable feature at Dulles International Airport (IAD) in northern Virginia, were also used at other airports, in this case at Baltimore-Washington International Airport (BWI) in Maryland.
During the special report, towards the end there is a close up of the air monitor and the New York satellite return monitor. Both monitors are in perfect synchronization. If the satellite return was indeed a true satellite return (and probably analog at the time) there would have been at least a 1 1/2 to 2 second delay due to the latency of transmitting and receiving the satellite feed. Odds are most DC bureaus were connected to New York via AT&T longlines as fiber wasn't really in vogue at the time.