Why is the closure of "Hands" ironic? How does the author prepare the reader for this irony?

The ending of Sherwood Anderson's "Hands," from his book Winesburg, Ohio, is ironic for a few reasons. Wing Biddlebaum, the main character, lives in fear due to a misunderstanding. As a younger man named Adolph Myers, he was a teacher in a small town. As he taught, he talked very expressively, and his hands "were a part of the schoolmaster's effort to carry a dream into the young minds. By the caress that was in his fingers he expressed himself." However, because "[a] half-witted boy of the school became enamored of the young master" and "imagined unspeakable things and in the morning went forth to tell his dreams as facts," accusations of molestation rose up, and Adolph was chased out of town and nearly hanged. He has resided in Winesburg for a long time, and he lives in constant fear that those who chased him out of the town will find him. Also, because he is not only innocent of the crime but also innocent in thought, he doesn't understand what he supposedly did wrong; he only knows it has something to do with his hands. At the end of the story, Anderson writes,

Lighting a lamp, Wing Biddlebaum washed the few dishes soiled by his simple meal and, setting up a folding cot by the screen door that led to the porch, prepared to undress for the night. A few stray white bread crumbs lay on the cleanly washed floor by the table; putting the lamp upon a low stool he began to pick up the crumbs, carrying them to his mouth one by one with unbelievable rapidity. In the dense blotch of light beneath the table, the kneeling figure looked like a priest engaged in some service of his church. The nervous expressive fingers, flashing in and out of the light, might well have been mistaken for the fingers of the devotee going swiftly through decade after decade of his rosary.

Once we understand Wing's history, the irony becomes apparent. He is wholly innocent of the accusations against him; he doesn't understand the accusations because he would never even think of doing the things he was accused of. He lives in fear of his hands and the effects of their actions, so much that he doesn't even sleep in a bedroom. Rather, he sleeps on a folding cot by the door, in case someone should try to enter or he should need to get out quickly, as he had to when he was accused and assaulted as a younger man. Furthermore, despite his innocence, Wing lives a penitent life for the sin he never committed. He constantly suffers because of his hands, though they have done nothing wrong. Anderson alludes to this in comparing him to a devotee constantly going through his rosary. His actions in picking up the crumbs illuminate how cautious and clean he is, but the vehicle with which he cleans—his hands—is the very thing that makes him feel careless and dirty.