Other mistake: Jesus leaves his home with a double barrel break-action shotgun and an ammunition belt holding extra shot-shells. In the next scene Jesus is walking in the street with the shotgun and no ammunition belt, it magically vanished. The shotgun only has a capacity for 2 shot-shells, then it needs to be reloaded, or it can be reloaded after one is only fired, that procedure is called a top-off. He fires 1 round at the mayor and two inside Elena's home which makes three. He never reloads. (00:32:50 - 00:34:40)
Other mistake: Edmund and Dolly make love in the barn completely naked. Yet the next shot is morning and Dolly is suddenly wearing a camisole after they've awakened. Which wouldn't be the case after falling asleep after sex They'd both still be nude.
Episode #1.7 - S1-E7
Other mistake: Surveillance cameras are shown on monitors when the mass panic kicks in even though any chip-dependent electronics shouldn't work in the game world (previously stated by Chotu). (00:08:20)
Episode #1.4 - S1-E4
Other mistake: Kang-bae is shown following Yeo-rin whilst walking on the sidewalk. He looks at his hands for a few seconds, then when he looks back up, he realises Yeo-rin has noticed him, turned around, walked towards him and is standing directly in front of him. There's no way he wouldn't have noticed her whilst she was walking up to him. Even if he was looking at his hands, he should have seen her walking to him in the corner of his eye or at the very least, heard her walking up to him. (00:13:00)