Final answer:
Director Atom Egoyan excluded the final chapter in the film adaptation of 'The Sweet Hereafter' likely due to reasoning about tone, constraints of the film medium, or for artistic impact. The specifics of his decision were not given.
Step-by-step explanation:
In the film version of The Sweet Hereafter, director Atom Egoyan made a creative choice to exclude the final chapter from the narrative. While the specifics of his decision aren't provided in the question, it's not uncommon for film adaptations to diverge from their source material to better suit the medium or the director's artistic vision.
In general, changes like this could be due to a variety of reasons, such as reaoning that the chapter does not fit the tone he wishes to convey, constraints such as length and pacing, or a desire to leave the story on a note that prompts audience reflection.