Throughout the entire movie blood is spraying and gushing out of people getting killed, but whenever the ground is shown there are only a few drops of blood. The amount of blood being shown would create puddles on the ground.
In the scene where Mika is having lunch with Maslow in the park, the amount of Maslow's drink keeps changing between takes.
Early on in the movie, Mika drives a Volkswagen Eos. Later on in the movie, this car inexplicably changes to a Volkswagen CC (Passat CC in Europe), as seen in the chase/crash scenes out of the warehouse.
In the final fights with Raizo, Takeshi, and other ninjas, Raizo kills the ninjas and blood is shown. In subsequent shots of the whole setting during the fight, the blood disappears and reappears subsequently.
After Raizo slashes Ozunu's face when he leaves the clan, he blinds Ozunu's right eye, leaving it white. In the final confrontation, when Raizo delivers the final blow, Ozunu's eye is back to its regular color.
Europol is a relatively small organization without executive powers, established to facilitate information and intelligence sharing between Europe's various national law enforcement agencies. It does not conduct criminal investigations, operate prison facilities or command paramilitary units.
In the hotel, Mika tells Raizo that she doesn't smoke. Later in the movie when Raizo is recovering on the bed, Mika is seen smoking. However, this due to her doing what Raizo had earlier done for her, masking her scent with smoke from a cigarette.
Since Mika gave Raizo the homing capsule, his former ninja colleagues shouldn't have been able to leave the country with him. However, the authorities would have had to let the clan take Raizo back to their home dojo in order to locate it.
When the German Police arrives at the hotel, the sirens sound like American sirens. However, German police cars have a completely different sound.
Raizo is making tea. The teapot whistles. But when Raizo takes the teapot from the stove, there is no whistle on the teapot's spout.
When Raizo is training in his apartment, after the final katana spin, the camera shows Raizo face-on and you can clearly see he has an empty hand.
There is one shot of Raizo walking through Berlin that was probably not shot on location, as the German in the advertisement in the shop window behind him is nonsensical.
When young Raizo has his feet beaten bloody by the master, that night he is shown in his floor mat bed in the dormitory suffering in pain with bloody feet, but the aisle between the two rows of mats full of other ninja boy trainees has no bloody footprints showing where he walked to his bed.
In the scene where Mika gets back into the car in the parking garage of the warehouse, when the Ninjas start to attack her car and she starts it by pushing the start button, the Tachometer swings to the right and appears to "rev up". Therefore the sound effects man put a revving engine noise into the scene. The tachometer going to the right is just a test at start up of the car.
When Raizo is training in his apartment, after the final katana spin, you hear the clang of a katana hitting stone when it should be hitting a wooden floor.
In the scene where Mika enters her home after the power cut, as Mika enters the apartment she shines her torch into her home whilst shutting the door behind her. The light clearly reflects off the camera and lights up the corner of the room behind her.
When Mika enters her home after the power cut, as Mika enters the apartment she shines her torch into her home whilst shutting the door behind her. The light clearly reflects off the camera and lights up the corner of the room behind her.
Europol headquarters is located in The Hague, not Berlin.
When Raizo gets Mika's photo, he reads her address in Berlin on the back side: "Mika Coretti, Götzstr. 165, Alexanderplatz, 10179." When Mika reaches her home in the night we see a street sign named "Motzstrasse". Götzstrasse has the postcode 12099, Alexanderplatz has 10178 and Motzstrasse has 10779. Both streets are not even near Alexanderplatz: Götzstrasse is in Tempelhof district, Motzstrasse in Wilmersdorf district.
Early on, Ozunu demonstrates his mastery over his flesh by cutting his palm and then healing it almost instantly. Yet after Raizo slices Ozunu's face with his blade, the facial scar remains for some time afterwards. If Ozunu had enough skill to heal his wounds, he should have had no scar at all.
When Mika and Raizo were trying to flee the warehouse where Raizo was being held in custody for interrogation, Raizo seemed to know where Mika's Car was located even though he wasn't supposed to.