From: Rabbi Moshe Sofer
To: Unknown recipient
The Chasam Sofer resolves Tosfos' question on Kesubos 92b — why it matters to a creditor whether he litigates with the seller or the purchaser — by invoking the rule that contradicting documents disadvantage the holder (yad ba'al ha'shtar al ha'tachtonah). By collecting from the purchaser using the smaller document first, the creditor effectively neutralizes the contradiction and can later pursue the seller with only the larger document unchallenged. He also resolves a question regarding the Gemara's proof in Avodah Zarah that non-dangerous large animals may be sold to non-Jews, based on the distinction between mechamer and shevisas behemto during the nisyoni period.
Source: Shu"t Chasam Sofer CM §46