In plot, the falling action is the series of events that happen after the climax, or turning point.  This action precedes the denouement, or resolution in the plot in which the conflict ends.  So, with the climax of "Good Country People" being the point at which the itinerant bible salesman Manley Pointer steals the artificial leg of Hulga, trapping her in the loft by her physical handicap along with her spiritual incapacity, the falling action begins as Hulga, bereft of what has made her an individual, is left with nothing in which to believe. 

Turning to Hulga, the salesman tells her,

"You aint so smart.  I been believing in nothing ever since I was born!"

He descends the loft and Hulga sees his "blue figure struggling successfully over the green speckled lake.  Later Mrs. Hopewell and Mrs. Freeman see him come from the woods and head to the freeway.