From: Rabbi Akiva Eiger
To: Unknown recipient
Rabbi Akiva Eiger engages with his son-in-law's (the Chasam Sofer's) resolution of the Ritva's question regarding the pesach pasuach case: why the Gemara invokes the chazakah of ein adam torei'ach when the wife should already be disbelieved in a bari u'bari situation. The Chasam Sofer proposed that the chazakah is needed to defeat the wife's migo of mukas eitz, as advanced by Tosfos. Rabbi Akiva Eiger accepts the ingenuity of this answer but demonstrates it is insufficient, showing that under the first lishna in Kesubos 12b — where Rabban Gamliel's ruling is based on migo — the claim of mukas eitz tachtecha lacks its own migo and is therefore not independently believed, leaving the Ritva's question unresolved under that lishna.
Source: Shu"t Rabbi Akiva Eiger §200