Visible crew/equipment: The white safety wire attached to XXXX can be seen when the camera pulls up after he is dangled over the edge of the building by Eddie Temple's thugs.
Continuity mistake: When XXXX and Gene are drinking at Gene's apartment, the whiskey bottles change positions between shots.
Audio problem: When XXXX is drinking whiskey at Gene's flat, XXXX's mouth moves before he takes a drink but there is no sound, the audio of "You find peace with guns" is said whilst XXXX is drinking.
Continuity mistake: Dragan shoots XXXX's sniper - he is shown, dead, to XXX's right. Then, during the telephone conversation which follows, the sniper's suitcase is to the right of XXXX but the body is not to be seen.
Answer: Because the logo's a car registration plate and a number fits that structure better than just letters.