I think that the movie did a good job of addressing the issue of Dave's trauma throughout his life. Eastwood's use of flashback, shadows, as well as different lighting techniques brought out the struggle that Dave endures with his past. In the end, Dave's inability to fully confront his past and find a way to make peace with it is what causes him to kill that night. While he did not kill Celeste, the fact that he was shut off from so many others and could not relate to anyone else because of what happened to him is what causes him to be seen as suspicious. This misunderstanding might have been inevitable, but the fact that Dave cannot articulate it to others fully or even to himself is something that was brought out in the film. At the same time, I think that the film did a wonderful job of bringing out Jimmy's trauma at dealing with the loss of his daughter. In the end, both Jimmy and Dave demonstrate an inability to fully address their own pain and suffering in psychologically productive manners. They both succumb to violence as a way of dealing with their own pain. The film brings this out nicely and offers a further note of disquietude. In the book, Celeste approaches Sean about the murder of Dave at Jimmy's hands. Sean promises to bring Jimmy to justice. Yet, in the film, the pain of trauma is evident as Celeste wanders in the crowd aimlessly. Whereas some level of moral order might be evident in the book's ending, the true nature of trauma as difficult to define, yet whose presence is everywhere is brought out in the ending of the film, where Jimmy and Sean's eyes meet with a smile across Jimmy's face, pointing at Sean. While there might be structure and order in their worlds, Celeste's is fragmented and without recourse. The film's ending seems to suggest that trauma never ends to a great extent. What plagued Dave now hovers over Celeste. This might be one of the points of divergence between book and film.