Continuity mistake: Whilst Jung-seok is driving with his family on the first day of the zombie outbreak, after he says "All other roads must be blocked", his sister looks to the left to face her son in the back seat. The shot then cuts to focus on Jung-seok, and the sister can now be seen looking straight forwards out the window. (00:01:45)
Continuity mistake: Bernice's bangs go back and forth between having a small section separated from the rest to not separated. Before she kisses Thomas, her bangs are separated, but combed together when they are done kissing. (00:21:56)
Continuity mistake: Brandon has sweat across the back of his T-shirt from his neck to above the arm pits (areas that were wet were darker blue) when Aidan tells him he had to leave his apartment. When Brandon turns around to leave, his shirt isn't as dark where it was wet, but now he has a V-shaped area of blood down the back of his shirt and his underarms and waist gradually get darker (wetter with sweat). (00:07:28)
Continuity mistake: The amount and location of dirt on Christine's face is inconsistent, ranging from being very thick and obvious to barely visible, if at all. Sometimes it extends down her neck on the right side. When her hair covers most of her face, no dirt is visible - until she turns her head and the hair is away from her face. The intensity and location of the redness on her neck also varies. (00:03:31 - 00:04:48)
Continuity mistake: During the final fight at the very end of the film, pay attention to Millie's bloody nose. At first, there's an equal amount on either side. But a few seconds later, the suddenly less blood on the left side of her face and more blood on the right side.
Continuity mistake: After Wes was clobbered and on the floor, he had a long stream of water/mucus coming out of his nose or mouth and his lips were wet when he was standing up, but his lips/mouth/nose were totally dry when the killer put his gloved hand over Wes' right shoulder. (00:33:40)
Continuity mistake: The direction of the desk lamp's flexible neck varies with the camera's angle. Front views of Rodger show the top of the neck aimed toward the outer edge (length) of the desk and rear views of Rodger show the top of the desk lamp's neck pointed toward him sitting at the desk. (01:02:00)
Continuity mistake: Kelly was wearing a white thermal top over a white sleeveless undershirt. After he was thrown into the garbage can, his white thermal top was wet against his back, so he was no longer wearing the undershirt. (00:03:54 - 00:05:43)
Continuity mistake: Yi-Na had her head turned to the right while her dad Sang-Won was talking to her from the front seat and, eventually, Yi-Na closed her eyes. After a camera shift, Yi-Na's eyes were still closed, but her head was turned to the left. (00:04:17)
Continuity mistake: After PJ lets Officers John and Julia inside, there are a few continuity errors with the box on the table and the lamp's cord. Initially, the white evidence box is flush with the counter and the front side (with a hand slot) is facing the lower right corner of the screen. Later, the box is closer to the edge and the front side has been turned about 45°. The lamp's cord is sometimes flat on the table but other times there are two upward loops. The box and cord each change a few times. (00:34:09 - 00:35:15)