How does black comedy contribute to the tone and mood of The 100-Year-Old Man Who Climbed Out the Window and Disappeared?

Allan gives the command and Sonya sits atop Bucket, crushing him to death. The black humor is important to the book's tone, as otherwise, Allan's command for Sonya the elephant to sit and crush Bucket seems murderous and unduly harsh. Because the moment is played for laughs and surrealism, however, Bucket's horrific death reads as darkly comedic, and Allan does not seem murderous as, after all, Bucket is waving a gun at his friends.