From: Rabbi Moshe Sofer
To: Unknown recipient
When both simanim are fully cut but the shechitah is invalidated, the intestines are ever min hachai and may not be sold to a non-Jew. When flesh remains attached by a minority of the latter siman, it has the status of ever hameduldul, which is only rabbinically prohibited, and sale is permitted. The Chasam Sofer refutes the correspondent's argument that a punctured esophagus renders the animal like a lizard's severed tail, citing the Pri Megadim's distinction that such animals do not convey corpse-impurity, proving life-force remains and the flesh is ever min hachai forbidden to Bnei Noach.
Source: Shu"t Chasam Sofer YD §18