Continuity mistake: In the railway station where 47 is being followed by the FSB, Interpol and the older agent, you see the older agent running down the ramp to platform 9 after 47. His jacket is flying up in the back, and there is no weapon visible. When he stops running, he reaches behind him into the waistband and produces a handgun with a silencer.
Continuity mistake: Near the end, in the church tower, after the inspector arrests 47 and he is escorted by the soldiers from the tower room to the van outside, the inspector remains in the tower room while the soldiers, together with 47, leave. Next, we see 47 and the soldiers walk down the steps of the church building and head to the waiting vehicle - and the inspector is already there waiting for them. He couldn't have beaten the soldiers to the car; they left first.Allister Cooper, 2011
Continuity mistake: When the helicopter gunship shoots through the window of the cathedral's tower, bullets are seen to pass through Belicoff, leaving his chest in the direction he is facing. However, when the camera angle changes, the helicopter is to his side, at 90 degrees from the shooting in the previous shot.
Continuity mistake: When Agent 47 snipes Belicoff soon after the beginning of the film, he shoots the guard to Belicoff's left first, to allow a clean shot at the president himself. However, when the camera zooms to 47, you can see that he is directly in front of Belicoff, not to his side, so he needn't have shot the guard first; he already had a clean shot, and shooting the guard first only served to break his cover.