From: Rabbi Moshe Sofer
To: Unknown recipient
A shochet who repeatedly failed to detect knife nicks after slaughter had eight animals declared permissible, but a youth and shamash independently found the knife full of nicks. The Chasam Sofer rules all eight animals are doubtful neveilah: since the last animal is prohibited by two witnesses and the shochet's inter-slaughter knife checks were unreliable due to post-slaughter weakness, the lost-knife leniency collapses. Regarding absorbed vessels, he permits leniency in cases of great financial loss given the dispute over whether ta'am ke'ikar is a Torah prohibition.
Source: Shu"t Chasam Sofer YD §3