Factual error: On the ferry boat ride, which should have been from Canada to the United States, they were aboard a North Carolina ferry... The North Carolina flag was flapping in the wind next to the US flag. There was a closeup, and you could even see the name of the boat, which is named after a North Carolina Governor.
Continuity mistake: During the briefing on the hood of the car, after the regatta, both Mulqueen and McMurphy change positions at the cut from wide to closeup. Mulqueen is at the side of the car in the wide then in front in the close up. McMurphy is about a foot behind Preston in the wide to right beside him in the closeup then back again. Also Koslova lights her cigarette twice during the scene.