While at work at the Pentagon Linda Trip says to Monica "Lets take a walk." The next scene is them walking at the Tidal Basin across from the Jefferson Memorial. To walk from the Pentagon to the Tidal Basin would take at least an hour. Further, as the Pentagon itself is a huge building, it would take a considerable amount of time just to walk from their office to an exit. So, to take a walk from their office to the Tidal Basin is going to be 70 to 80 minutes, one way! That is hardly just "walking out the door," as the chronology of the series would have one believe.