From: Rabbi Akiva Eiger
To: Kalish
Rabbi Akiva Eiger rejects the correspondent's challenge to Rabbeinu Tam's explanation that slaughter on Shabbos is not mekalkel because the tikkun of removing evar min hachai occurs simultaneously with the kalkala. He demonstrates, relying on the Toras Chaim, Tevuas Shor, and Pri Megadim, that mefarcheses is permitted to a Ben Noach wherever valid shem shechitah applies — including slaughter for idolatry — so the tikkun is indeed simultaneous. He adds a second answer that Rabbeinu Tam's requirement reflects only R' Yehuda's view, while the baraisa of triple liability may follow R' Shimon.
Source: Shu"t Rabbi Akiva Eiger §165