Continuity mistake: When Hina turns around to stab the man behind her, it is revealed that it was Dong-mae, who grabs onto her arm. At first, we can see his hand is positioned a few inches away from her the edge of her sleeve. The next shot, he is holding onto the edge of the sleeve. Then in the shot after that, he is a few inches away from the edge of the sleeve. (00:06:33)
Other mistake: Dong-mae grabs a sword and slits the throat of a Japanese man, which causes blood to get splattered over both the left and right side of his face, as well as his neck and his chest. This would not be possible for multiple reasons. One, the slit was relatively small, so there wouldn't have been that much blood. Two, Dong-mae was standing too far away from him for the blood to travel that far. Three, Dong-mae had his head turned away from the man when he slit his throat. (00:43:19)
Continuity mistake: When Eugene begins eating the piece of paper, in one shot some of the paper can still be seen outside his mouth. When the shot cuts to focus on Moore, none of the paper can be seen outside his mouth. It is now entirely in his mouth even though it wasn't in the previous shot. (00:53:13)
Continuity mistake: When Eugene finds the note from Ae-sin in the barn, in the shots where the camera is on him, he is holding the paper near the top. When the camera is on the paper, his hand is nearer towards the middle of the page. (01:10:02)
