Other mistake: When the characters go to the Himalayas, the whole time, like for 20 mins, including the confrontation scene, they are all wearing casual, short-sleeved shirts. You can see Mr. Burnish's henchmen wearing winter clothing, while the main characters don't freeze to death. They only start getting cold after a long time.
Continuity mistake: The protagonists escaped from captivity and managed to return to Harry's palace. Luka decides to leave to go look for his mother. Harry seems to send him off, and he is standing in the middle of the stairs, about 4 steps below the guard. Harry at this point is in close-up; the guard is not visible, and at the next cut somehow Harry shoves him off as if he were standing directly behind him. (00:16:00)
Continuity mistake: In the prologue, the Nazis storm the Bresson residence. The elder Professor Bresson is sitting at his desk, back turned to them. There's an open fountain pen next to him, right by a paper sheet, but when Bresson answers rather defiantly to the bad guys, the paper sheet suddenly has disappeared. (00:02:15)