After Mary spills her glass at lunch (back to camera), the liquid soaks the table cloth hanging several inches over the edge of the table. In the next shot, she's blotting the stain (face to camera), and there's a good inch of dry tablecloth between the stain and the edge of the table.
In the very beginning of the film, when James sits, his cigar jumps from the left to the right hand.
When James and Mary sit on the swinging bench, James' left hand jumps to his mouth.
After James gives Edmund cash, the way that Edmund holds it changes between shots.
As Edmund pockets the money from James, he flashes it in the left hand, but pockets it with the right.
In the climatic final scene as Mary wanders about her empty house, the shadow of a crew member is visible in the room.
A shadow of the boom microphone can be seen moving on the wall and picture behind Mary as she sits in the rocking chair after getting back from her trip to the drug store.