Her brother, in a casual remark, later refers to her torrid past. There's been no hint of that side of her personality until the comment, which she then obediently proceeds to justify. Sammy's son is relentlessly deadpan and her lover somewhat absurd, a bit of a caricature. That an overbearing bank manager, a maddening stickler for rules and regulations, attached to a highly pregnant wife, should suddenly take up with his female loan officer and spend afternoons and evenings with her at a local motel, seems unlikely. Such things happen, of course.
Life is contradictory.
The filmmaker wants to have his cake and eat it too. People commit reckless, irrational acts here, which provide a certain amount of dramatic mileage, but then they prove to be conventional and predictable, after all. Perhaps such behavior might hint at other possibilities, at unhappiness, at dissatisfaction. No, Lonergan allows the bank manager to return to his old existence without his inner or outer life undergoing any serious consideration. There's something cheap about that.