Peter discovers that the bomb on the DC Metro train car he found was supposed to go off somewhere along Wilson Blvd. However, he boarded the train with the bomb at the Gallery Place - Chinatown station through which the Yellow and Red lines pass. It's the Orange line which travels along Wilson Blvd.
Peter, Rose and Lorna are walking on a Washington street when a Canada Post van drives by in the background.
When Peter, Rose, and Lorna are driving away from Lorna's house, she instructs Peter to "take the next exit." However, the overhead shot had already established that they were on a two-lane country road, not a highway with exits.
When Rose and Peter are shown in front of the library at Maddie's Washington, DC area university, the library is in fact the Walter C Koerner Library at the University of British Columbia in Vancouver, Canada.
A Canada Post vehicle passes by on the street.