The Gemoro on 98a (7 lines up), says that if we require kefira bemiktzas, the borrower would have to deny that one animal was ever taken (LaHaDaM). Could he not say that one animal died at the time of hiring?
Meir Eliezer Bergman
Manchester UK
Rashi (DH u'l'Rami) adds that Hechezarti also qualifies as a Kefirah. I agree that if the Socher would say that one animal died when it was in Sechirus, this would be classified as a Kefirah.
Dov Freedman