When the lady is impaled in the chair, the amount of blood all over her clothes changes by the end of the scene. Blood all over her right arm vanishes.
When the second spike impales the lady in the chair, the sheets of paper on the floor move further away from the spike between shots.
When the blade swings down into the side of Mako's face, the blood clearly flows down from the top of the blade, and not from her face.
When the woman is impaled with all of the spikes, in the chair, it is obvious that she is keeping one tucked under her arm, in order to keep it up.