A very short story, what it means, and why it works

Trying to get at the  unusual qualities of James Kelman's short stories (in Greyhound for Breakfast), which, as noted in previous posts, give voice to the marginal, to the down and out work-class people, men almost always, in contemporary Glasgow. From title of book you can see that Kelman is deft and provocative with titles; some of the pieces are extremely short and seem more like fragments of even prose poems, on for ex., that's a paragraph long only with the title The Man for Fuck Sake and which begins: "This man for fuck sake it was terrible seeming him walk down the edge of the pavement." Check the rhythm of that sentence and how it conveys the pattern of thought (if that's the right word) and the rough cadence of voice: not a man but "this man" - particularizing, pointing out; the interpolated "for fuck sake" not only there for its vulgarity but to add a sense of pity, we feel sorry for "this man" so obviously impaired but what can you do about it? Yes, "it was terrible" just to see him walk - but now his walking is some undefined time in the past - "this man" becomes "that man," in a sense. And why was it terrible? Because he was on the "edge of the pavement" - there no doubt because the speaker and his "mates" were walking, toward him?, down the middle of the pavement and "this man" was trying to avoid them. The paragraph/story ends: "How can you blame us? You can't, you can't fucking blame us." So "they" did some harm to "this man" - robbing him, injuring him, pushing him into traffic? It's unstated - though we think back to the first story in the collection about three toughs who rough up a guy sitting on a park bench, and the many moments in these stories of someone asking a weaker counterpart for a cigarette or for some money - but in this story there was, apparently, an act of violence, never described though, just left aside and ending in the pathetic but frightening apologia. Why can't we blame them, why shouldn't we? Because their world is one of chance and opportunity - why wouldn't they rob this guy, he made it so easy? He was natural prey. The broader question is: whom is the speaker addressing? He seems to be speaking almost to himself, or perhaps to a fellow drinker in a pub - and trying to convince himself that he should be blameless, but in a sense making his case worse: we do blame him, we feel sorry for the man on the edge of the pavement, who could be anyone, any of us, at any time.