After Agent 47 finishes talking to Nika in the car, the scene cuts to the car from the rear driving away. The Audi that is driving away is an RS4 Cabriolet. It is the same car Agent 47 uses while going to the Palace of Udre but not the car which he stole from Belicoff's man. That was an Audi S5.
Near the end of the film, when Interpol Inspector Michael Whittier is
sitting in the ambulance, his shirt is open, he then is shown to be buttoning it closed, but in the next shot (from far away) his shirt is still completely open. In the next shot, from up close as he stands his shirt is completely buttoned closed again.
In the train fight scene, after Agent 47 kicks the other blade wielding agent out of the train window. Agent 47 removes the (very bloody) blades he had already used, from the other dead agents. However after he gets down, below train level, to begin fighting once again, the blades appear clean.
When Agent 47 kills Udre Bellicoff, he has blood splatters on the collar of his white shirt. In the next scene, when he returns to the hotel and sits on the bed, there is no blood visible on his clothing.
When Nika and Agent 47 are in the car and she's eating a sandwich, a moment later you see Nika and on the closeup on her face you see a blond hair sticking out of the right side of her mouth (was she eating a hairy sandwich?). The camera changes to Agent 47 and then back to Nika and the hair's gone.
At one point, Agent Jenkins informs Agent Whittier that Udre Belicoff was found dead "3 hours ago."
A minute later, a television broadcast states that Mikhail Belicoff will "attend the funeral of his brother Udre, who died two days ago."
President Belicoff speaks to a reporter in a middle of a large
demonstration of protesters, supposedly in Russia. But the sign on the building is in Bulgarian - "Ivan Vazov National Theatre", which is, in fact, located in Sofia, Bulgaria.
The interpol agents and St. Petersburg police discuss intercepting Agent 47 at the St. Petersburg Station. However there is no St. Petersburg train station in St. Petersburg. The train station shown on the map is the Moscow Station, located in Revolution Square whereas the Leningrad (the former name for St. Petersburg) station is located in Moscow. This is because in Russia, train stations are named after the main destination they serve (there is also a Kiev station in Moscow for example). They were designed by the same architect.
During the movie the teletype text says, "Russian Border - Turkey" This film takes place during modern times and Turkey does not border Russia but Bulgaria, among other countries. They could be referring to the Azerbaijan-Turkey border, as Azerbaijan is a member of the CIS, sometimes (incorrectly) referred to as "Russia", especially by Americans, but this would still be inaccurate.
When the interpol agent chases Agent 47 down the hallway of his hotel, he escapes by jumping through a window and dropping straight down into the canal below - however this is not possible in St. Petersburg. The canals do not run alongside buildings. The way the actual city is set up, alongside each channel of the canal is a sidewalk, then a street, then a wider sidewalk alongside the buildings. He would have had to jump nearly ten meters to make the water.
On the northern hemisphere (Istanbul), when the sun is rising, it should travel from left to right and can be seen on the southern sky. It seems that the rising sun in Istanbul-shot is filmed in the southern hemisphere.
Like many other movies portraying Interpol agents many mistakes are made concerning how Interpol works and operates. For example Interpol officers do not directly conduct inquiries in member countries and Interpol's constitution forbids its involvement in several types of crimes, such as political ones.
When the Hind gunship attacks Agent 47 in the church it has 4 UB-32 rocket launchers mounted on it. However when the camera fully shows the hind, muzzle flashes are seen from the rocket pods, even though they only fire rockets, and no rockets are fired as the ensuing explosions would have been quite noticeable.
In the meeting with Udre, an M16 type rifle with an M203 grenade launcher mounted is incorrectly referred to as an M203. The M203 can be directly attached to M4 and M16A2 rifles and some others as well using the M203PI system.
The opening credits is a mixture of footage created for the movie and clips from the TV show Dark Angel. Notice is in the barcodes: Hitman tattoos are above the neck and Dark Angel tattoos are on the neck itself.
In the first scene where children gets their first training there is a scene where it shows the famous tattoo is placed at the back of one of the children's neck. Later on it appears on the back of the head and much smaller.
In the scene in the hotel room in Turkey, when Nika gets up and stands on the balcony, Agent 47 is reading through papers on his target. In them Istanbul is spelt 'Istambul'. However, the name of "Istambul" is still used among many European countries.
While Agent 47 is posed as arms dealer Price, Udre Belicoff showcases several weapons. When he picks up the assault rifle, he describes it as an M203 with under-barrel grenade launcher. This is actually an M16 rifle, with M203 grenade launcher attachment. He also suggests that the rifle shoots 7.62 mm ammunition, when in fact the M16 shoots 5.56 mm. This is shown to be deliberate when 47 calls Udre out, saying "you've been wrong about most of these."
When 47 first interrogates Nika, it appears that the tattoo on her face switches sides during the scene. This is because the camera is viewing the characters directly in some shots and views them indirectly in other shots using the large mirror present in the room.
The light switch in Whittier's house (which is supposed to be in London), is a broad continental Europe style switch, instead of the smaller thinner switches you find for British lights. This indicates that the scene was filmed somewhere else.
The interior shot of the Alexander Nevsky Cathedral in which Belicoff delivers a eulogy for Udre was not actually taken inside the cathedral. The hall shown is much smaller and pillars can be seen that do not appear inside the real cathedral.