In "A Bottle of Milk for Mother," the ending is not optimistic. The law has certainly found enough evidence to convict Bruno, a young Polish gang member, of the murder of a drunk. And although the police know that he did not work alone, and although Bruno has tried to elicit their sympathy in portraying himself as a kid who messed up, the police end up treating Bruno like a number, like a "case closed"--closed on a young man who will most certainly be executed for murder.
At the end of the story Bruno is not praying when on his knees. He is there to pick up his hat, but symbolically, he is seen in the light of an animal facing his death. There is no "happy ending" in this story.