The component of the plot structure described in this excerpt is the falling action.
This is because the excerpt shows a moment of realization or consequence following the climax of the story. The protagonist, Gortsby, discovers the small packet on the ground, which likely leads to a resolution of the conflict or misunderstanding related to the youth he had previously encountered. The falling action typically occurs after the climax and leads towards the resolution, where the consequences of the climax are explored.