When Dr. Grauer goes to take his medicine, which Luise has brought him, he first had the bottle in his left hand, pouring it into a spoon in his right. However in the next closer shot, the spoon and bottle have switched hands.
At the 0:10:46 mark when Mrs. McGill is holding a book the closeup of the hand holding it has on dark nail polish, but Billie Burke appears to be wearing light-colored or no polish.
In the mountain climbing scene where Robert Young slips...every time he gets up, he casts a shadow on the backdrop of a "distant" mountain.