This is an important guest post by RaP providing a translation of Yiddish letter posted on Daas Torah about Weberman case.
Translation of Yiddish Letter About Weberman Case
[See post I & II] The starting point for the halacha of a wife who confesses being prohibited to her husband for adultery (or rape in the case of a cohen's wife) - is the Mishna (Nedarim 90b). This Mishna records that historically the normative halacha was that women were believed when they made such claims and thus the husband was required to divorce them and give them their kesuboa. However at some point in history, the halacha was changed because it was assumed that they might be lying in order to obtain an automatic divorce as well as the kesuba - because they wanted to marry someone else. The Rosh explains that the generations deteriorated and women now had no qualms about lying in order to get divorced and marry someone else. These sources clearly indicate the nature of marriage and divorce as well as the change of halacha in the face of social and psychogical changes in society. There is obviously much more - but this is the foundation that everything else is built upon.