Other mistake: Jung-seok's nephew accidentally drops a ball which rolls away and lands in front of a nearby bed. When he walks over to get it, he realises that the man sitting on the bed has turned into a zombie. He is shown in a contorted position, with his back lifted off the ground and is heard making painful grunting noises. The other passengers in the cabin then realise there is a zombie in the room with them. It is extremely hard to believe that none of the other passengers in the cabin would have noticed this beforehand, not even by accident. This man's body was in a completely inhuman and unrealistic position, but it's not until the nephew walks up to him where people start to notice. (00:05:25)
Other mistake: At the docks, when Min-jung is inside the truck that is surrounded by zombies, there is a moment shown from inside the truck where the helicopter is shown in the background. The helicopter is far off in the distance, but when Min-jung begins to put the machine gun under her chin to shoot herself with, Jung-seok and Min-jung's daughters (who are standing right next to the helicopter) can see exactly what Min-jung is doing inside the truck, even though it should be too far away for her to see what is going on. (01:45:13 - 01:45:39)