I think that isolation becomes a major element of Daniels' narrative.  He is not really understood as anything other than an indistinguishable man of color.  He, himself, does not even remember his name until the middle of the narrative.  There is little to show that he has people who miss his presence or that his identity is linked to anyone or anything else.  For all practical purposes, he goes through his existence in the short story isolated from all others.  Yet, I tend to think that the best example of his isolation actually comes at the end when he understands that someone else is being punished for his own transgression.  It is at this point where he is actually able to emerge from his own isolation, seeking to establish a moral order in a world that is sorely lacking.  It is at this point where he seeks to emerge as a part of something, even if not socially with others, to his own sense of righteousness and what he perceives to be a moral order that should be present.  Yet, in the end, his isolation is only confirmed when he is killed and his confession is discarded.  He is swept away, out of view, only because he sought to reconnect his own identity to something larger than himself.  It is here where I think that Daniels' isolation becomes most evident.  In the moment where he sought to take an active role to remove his isolation, he is forced to acquiesce to it.