I completed it by literally throwing her body in front of him. Found that particular solution on a walkthrough.
He's running around non-stop, and if he stops momentarily and I get the chance to throw her body at him, it hurts him for about 6 damage and he still doesn't acknowledge his wife's death after that.
Besides, this doesn't seem like the intended way to complete the quest, as the quest log says that he would want the ring back, so showing him the ring ought to be the way.
