Complex sentence: At the end she is proven wrong, as Gilbert's lack of attention was in fact caused by worry over one of his patients and he surprises her with an anniversary gift and a promise of a trip to Europe for a medical congress.
Split into simpler sentences: At the end she is proven wrong, as Gilbert's lack of attention was caused by worry over one of his patients. He surprises Anne with an anniversary gift and a promise of a trip to Europe for a medical congress.