(at around 46 mins) When Jade is talking to the cinema owner her hair is alternately behind her ear/hanging straight between shots.
(at around 1h 20 mins) When Bad Girl and Kar blow up the SUV by remote control, a brief wide shot shows no bad guys anywhere near it, but in the next shot several are tumbling away from the explosion.
(at around 36 mins) While the Monk and Kar talk as they walk down a crowded street, the same woman in a blue coat with a hood walks past them in the same direction several times.
(at around 1h 20 mins) When Nina and Kar blow up the car, the explosion starts with the man outside before the car blows up.
(at around 1h 30 mins) When the monk is holding onto the pipe the Nazi is hanging onto the Nazi slips off and the monk has one hand off of the pipe but in the next scene he has both hands on the pipe. This happens quickly but it is noticeable.
(at around 55 mins) When Struker is reading the recipe for chicken soup, he is holding the scroll upside down.
(at around 1h 16 mins) When Nina talks to the captured Nameless Monk, she shows him two newspaper clippings. The leftmost clipping, titled 'Unknown Asian Man Saves Three Children' has the lyrics to Sunscreen as the body text below the author's name.
(at around 1h 18 mins) As Jade and Kar chit-chat and drive down the freeway in her SUV to rescue Monk, a quick shot of the window behind Jade shows the vehicle is not moving.
(at around 1h 24 mins) When Jade and Nina fight in the tunnel, one of the blades is seen wobbling indicating an obvious rubber prop knife.
(at around 1h 25 mins) After the monk has been thrown against a brick wall by Struker, the bricks crumbling from the impact can be seen to be actually brick tiles.
(at around 1h 10 mins) At the inside shot of Kar climbing through Jade's window when he lets go with his hands he appears to be quite well supported, even though the previous outside shot showed there was nothing for him stand on outside.
(at around 52 mins) During the fight on the rooftop, when Kar falls over the side of the building, you can see a PA dressed in his traffic gear in the middle of the intersection in the top left corner of the screen.
(at around 14 mins) The train that passes by in the subway tunnel, clearly says Kipling, which is a station in the Toronto, Canada subway system, and is not the city in which the movie is set.
(at around 1h 6 mins) While Monk and Kar are on the boat at night you can see Toronto's CN Tower.
Several of the Nazis carry Desert Eagle pistols made by Israeli Military Industries.