The cargo aircraft that was to transport the chemicals is described verbally as a 737. Yet the aircraft that is shown being loaded with those chemicals has three engines.
When Mark returns to the Embassy with Sinclair's little boy, and takes the boy to the room where he can stay, you can hear European Blackbirds (Turdus merula) and Great and Blue Tits (Parus major and caeruleus) singing from outside - these birds and their singing don't exist in Washington D. C. - but they exist in Great Britain.
When Sinclair is traced, the map shows he is in Cape Charles, VA. Later when his body is found, the FBI agent states it was found in the Potomac, which is over 100 miles NW and across the Chesapeake Bay.