When Eva and Lucas first go to New York, the scene is set by an American flag hanging from the corner of a building. Unfortunately, it is a 50-star flag, which did not come into use until Hawaii was admitted as the 50th state in 1960.
When Eva is crossing the border from New York state into Quebec, on the west side of Lake Champlain, we see a majestic mountain range on her left, or west, side. There is no such mountain range anywhere nearby, much less between Champlain and the St. Lawrence river.
The notice of Romer's memorial service shows his awards as KCB, MC and Bar, Croix de Guerre. The order of precedence is strict, and the awards should have been in the order OM (Order of Merit), KCB (Knight Commander, the Most Honourable Order of the Bath), Military Cross and Bar, Croix de Guerre.