In Jane (2014), the flashbacks of which occur after those of this episode, Angus asked Luke if there was ever someone whom he had "thought might be a keeper?" Luke responded, "There might have been one girl, once, but she was going out with someone else." In the flashbacks of this episode, it is revealed the Luke was on the verge of proposing to his girlfriend of three years. Clearly he thought that she was a keeper, and the problem was not that she was going out with someone else. It is unlikely he would have forgotten about his girlfriend of three years who broke his heart.