Continuity mistake: In the intro, Illya shows Solo an automatic rifle he's retrieved after the shoot-out in the mausoleum. In full shot, he's holding his U.N.C.L.E. Special pistol in his right hand as he points to the logo on the rifle's stock. In the close-up insert of his hand, the Special disappears.
Revealing mistake: During the foot-chase through Tenza HQ, the Thrush gunman, with Illya in hot pursuit, races around a hallway corner. As Illya runs into the shot, the gunman's shadow reappears on the back wall, revealing the fact that the actor has stopped and is standing back there. Next shot, though, he's running down another corridor and through a door.