Given the situation where the wife and the husband have grown apart over time and the wife has had an affair, but for whatever reason, she returns to the marriage. Harley's advice is:
Nowhere in this advice does he say to assume she is lying when she says the affair is over. He says to be nice, try to meet her needs. Because the person she enjoys being with is the person she will want to be with.
You are taking that out of context. Harley discusses withdrawal phase in depth two which you have bypassed without so much as a mention.