When Sarah is beating Ashley with the free weight, it is covered in blood. But as she hesitates with the weight in the air before delivering the final blow, you see the weight has no blood or gore on it.
When Sarah was in the office of Tater Tots discussing her future as a waitress with the manager, a schedule of names with their hours are a board in the background behind the manager. Later on, when she's back in the same office again, asking the manager for her job back after she quit, Sarah's name along with the number of hours are still on that board.