Episode #1.1 - S1-E1
Other mistake: Kang-bae runs up to the store manager with a trolley to stop him slashing Weol-ju with a knife. When the manager falls backwards into the trolley, he is holding the knife in his hand and then drops it on the ground. His hand is positioned towards the back of the trolley (where the handles are), but the knife that fell out of his hand lands on the ground in front of the trolley when it should have landed towards the back of the trolley. (00:48:20)
Episode #1.1 - S1-E1
Other mistake: Weol-ju goes into the forest at night and sees her house has been set on fire. From where she is standing, there is a large distance between her and the house, and the fire is so huge, that she can see it all the way from the forest. She then runs back, and given the distance between the forest and the house, should have taken a while, but the house is still in the middle of burning down when she arrives. The fire should've definitely worsened during her run back to the house. (00:12:23)