In season 1, one of the subway car numbers involved in the Washington Metro subway bombing is car #2781. The Washington Metro 2000 series subway cars only had car numbers #2000 to #2075.
In the shoot-out in the hotel, Dale's gun has a suppressor ('silencer') but the sounds of his shots are not suppressed.
When Peter rescues Rose at the Hotel she is wearing a bath robe. Just doesn't make sense since she was expecting him for breakfast.
When Rose and Peter are driving from her uncle and aunt's house, the camera pans across a forest full of Western White Pine trees. These trees do not grow the eastern portion of North America, especially around Washington, DC.
29:10: As Peter takes Rose to a clothing store for her "wardrobe emergency", the "housekeeping" assassin looking for them is walking on street with a T bus stop in the background. Washington DC uses the M for MetroBus, the Vancouver, BC bus system uses the T in their bus stops. Also the street regulation sign is not in Washington DC.
When Peter and Rose are escaping from the hotel safe house, they are not in the US. There is an exit sign in the hallway when they leave the room. It is not the red and white sign with the word EXIT. It is a green and white pictogram of a person and an arrow.