Episode #1.1 - S1-E1
Factual error: The American flag shown waving outside the White House is the current present-day flag with 50 stars. From 1896 to 1908, (the time period that this show is set in) the US flag only had 45 stars as Oklahoma, New Mexico, Nebraska, Alaska and Hawaii were not recognised as states in that time period. The flag did not have 50 stars until 1960. (00:04:30)
Factual error: When Eugene is searching through the drawers for the list of Joseon mobs, a book with Yogi Berra listed on the spine can be seen on top of the drawers. Yogi Berra didn't begin his baseball career until 1946, and he wasn't even born until 1925, over 20 years after this episode takes place. (00:18:40)
Factual error: Joseph is given an American military funeral. The coffin, when placed in the ground, is shown with an American flag placed on top of it. Eugene sprinkles some soil over the coffin (with the flag on top of it), however burial flags are always removed prior to the actual burial, folded and then handed to the next of kin, so the soil he sprinkled would not be included in the actual burial. (00:29:10)
Revealing mistake: When Eugene receives his return orders, not only is it from the wrong Roosevelt, but above the Eagle, it says the "State" of Washington rather than being from Washington DC, which is not a state. (01:08:16)
Plot hole: After Ae-sin shoots Wan-ik and flees, Hina shoots Dr. Matsuyama with a six-shooter and plants the gun in his hand to make it appear as if he shot both Wan-ik and himself in a murder-suicide. However, Ae-sin shot Wan-ik with a rifle, meaning the bullets that were used to shoot Wan-ik and the bullet that was used to shoot the doctor were completely different bullets; the authorities would realise this when an autopsy on the two is performed. (00:26:10)
Continuity mistake: When Mrs. Haman hugs Ae-sin after Sa-hong dies, in one shot, Haman is shown placing her right arm over Ae-sin's shoulder. When the camera changes angles, her arm is much lower down Ae-sin's torso. (00:55:03)
Continuity mistake: Wan-ik is being questioned by Deok-mun. After Wan-ik says "How am I supposed to read it when it's covered in blood", he places the bloodied note he is holding on the table. A couple seconds later, he is suddenly holding the note in his hands again. (00:05:54)
Continuity mistake: When Sa-hong catches Deok-mun threatening Ae-sun, in the shot of Deok-mun realising he is standing there, he has his hand raised in the air as he was about to hit Ae-sun. When it cuts to a wide shot, his hand is suddenly lowered. (00:44:59)
Continuity mistake: After Dong-mae has been shot and has a flashback to a greeting he had with Ae-sin, there is a streak of blood shown coming out of his mouth going down to the bottom of his chin. The shot cuts to Hui-seong, but when it cuts back to Dong-mae, two additional (smaller) streaks of blood have suddenly appeared next to the first blood streak. (01:08:13)
Continuity mistake: When Chun-sik and Il-sik find the stopwatch Hui-seong left for them to pay his rent with, the watch is shown being held against Il-sik's fingertips with his hand opened out. In the next shot, Il-sik's hand is suddenly clenched shut. (01:28:16)
Continuity mistake: When Hui-seong approaches the authorities who have Dong-mae tied up, Hui-seong raises his hat. The hat can be seen right in front of Dong-mae's face. When the camera changes angles, Dong-mae's face can be seen in the foreground, but the hat is no longer visible in frame. (00:11:30)
Continuity mistake: When Eugene and Ae-sin are talking on the ice at the start, there is an accessory attached to Ae-sin's hat that is being blown by the wind. After Ae-sin asks "who said such a thing" and Eugene replies "Some nobleman", the accessory on her hat is suddenly still and is not affected by the wind. Then it is blowing in the wind again the shot after that. (00:01:45)
Episode #1.5 - S1-E5
Continuity mistake: Gwan-su and the interpreter get into a kerfuffle. Gwan-su is shown holding onto him with one hand, but in a wide shot, he is suddenly holding onto him with both hands. The interpreter is also suddenly holding onto Gwan-su, something he wasn't doing in the previous shot. (00:52:30)
Episode #1.4 - S1-E4
Continuity mistake: When all the people are in Eugene's office, a man walks up to Gwan-su and Gwan-su then brings him to Eugene. Gwan-su has his hand on the man's shoulder in one shot, but when the shot cuts, the hand is no longer there. (00:35:27)
Episode #1.3 - S1-E3
Continuity mistake: Whilst in the rowboat, Eugene splashes Ae-sin with some water. In a shot focusing on Eugene, Ae-sin can be seen placing her hand over her face. When the shot cuts, her hand is suddenly positioned to the right of her face. Then in the shot after that, her hand is away from her face completely. (00:42:22)
Episode #1.1 - S1-E1
Factual error: In the flashback that shows the fate of Ae-sin's parents whilst Ae-sin is a baby, several characters can be seen using a Mauser C96 pistol. These include the father when he tries to shoot Wan-ik, the mother when the soldiers come for her, and the man standing beside Wan-ik who shoots the father. The flashback takes place over 20 years before the main story takes place, which would have set it in the 1870s, but the Mauser C96 pistol was not first designed until 1895. (00:56:10 - 00:58:03)
Continuity mistake: When Chun-sik and Il-sik are talking with Nam-jong, they are both eating a corn-on-the-cob. In the shot of her saying "I heard that you do anything people need done", the cob that Chun-sik is holding is away from his face. But in the next shot, he is suddenly eating the cob. (00:40:32)
Continuity mistake: When Ae-sin is tending to the wound on Dong-mae's arm, she ties a piece of cloth around the wound. In the close-up of his arm, the knot is tied so that it is facing his sleeve. When the shot cuts, the knot has suddenly rotated 90°. (00:26:29)
Continuity mistake: When Ae-sin is in Hui-seong's room, and he is preparing an escape from her, in the shot where Hui-seong starts saying "I don't know if this will work", Ae-sin's hair can be seen going over her left shoulder. The shot cuts to Hui-seong, then when it cuts back to Ae-sin, her hair is now directly on her left shoulder. A couple of shots after that, her hair is suddenly over her left shoulder again. (00:07:18)
Continuity mistake: When Sa-hong pulls out the napkin used to tie Ae-sin's hair, some of her hair can be seen going over her shoulder. When the shot cuts, all of her hair is behind her shoulder. (00:12:26)
