From: Rabbi Moshe Sofer
To: Rabbi Ber
The Chasam Sofer rules that chezkas eino zavuach does not combine with the minority concern of nikuv ha'veshet to undermine the majority presumption that most animals are kosher, since rov independently establishes fitness for shechitah. He further demonstrates that nikuv ha'veshet constitutes a miuta d'miuta, and that under many authorities it is classified as treifah rather than neveilah, making the chezkas eino zavuach concern entirely moot. He dismisses the student's oso v'es bno argument and notes that lenient rulings apply only when no ri'usa was found in the animal.
Source: Shu"t Chasam Sofer YD §24