In the middle of the movie, when Farid escapes to the basement, he hits Karl in the face with a sledgehammer and knocks him down. Then, in the next scene Karl is sitting at the dinner table, with no mark of that stroke on his face.
After Yasmine escapes from the house and takes the elevator down into the shafts below, she leaves the outer elevator gate open, which is seen as the elevator is recalled to the surface by Karl. Later, after she kills Goetz on the table saw, Karl exits the elevator into the shaft, having to open the outer gate again, which is now closed.