Continuity mistake: When Helena is fighting all the guards on the staircase, there are knocked out guards and a samurai sword lying directly behind her foot. In the next shot, they are all to the side so that Helena can run down the steps.
Continuity mistake: Back at Kasumi's palace, in the close up Helena stands right next to Tina (you can see her hair) but in the next shot Ayane is standing between Tina and Helena.
Continuity mistake: When Helena is being scanned by the computer, you get to see multiple simultaneous angles of her on the computer screen. Her head movements in one of the images do not match what her head's doing in the others. (00:18:15)
Continuity mistake: When Kasumi is holding her sword at the throat of the purple haired girl at the start, her sword changes between shots. In the first shot, the blade is facing up. In the next, it is now flat. Not enough time has passed in between shots for this to have occurred. (00:03:15)
Continuity mistake: When Tina Armstrong kicks the two pirates off the yacht, she then adopts a classic fighting stance for the pirate leader. In the first shot she's leading with her left arm; in the next shot she's leading with her right arm. Not enough time has elapsed for this to occur. (00:06:25)
Continuity mistake: When Bass and Tina are fighting on the raft, the sky alternates between partly cloudy and totally overcast several times.