What is the Halacha if one shechted a sacrifice on Shabbos and found it to be a Treifa?

Question

I've seen three types of "Shogeg":

1. You don't realize it was Shabbos - for this you bring a Chatas.
2. You don't realize what you're doing is assur - for this you bring a Chatas.
3. You don't realize what you're doing altogether (you think you're picking up a detached blade of grass but it turned out it was attached, in other words, you didn't realize you were Kotzer) - nothing, it's Misasek.

What about if one Shechts a Korban (Tamid/Mussaf) and it turned out to be a Treifa (so one needs to bring another one)?

You know it's Shabbos, you know it's assur to Shecht, and you know what you're doing, yet to call it Meizid is kind of hard. What's the halacha?

Answer 1

The Mishna in Pesachim (6:6) discusses slaughtering a Korban Pesach on Shabbat and finding it to be a Tereifa. In the Rambam's ruling (Shegagot 2:10 (English)):

וכן השוחט את הפסח ביום ארבעה עשר שחל להיות בשבת, ונודע לו אחר כן שמשכו הבעלים את ידיהם או מתו או נטמאו קודם שחיטה, או שנמצא טריפה בסתר, כגון ניקוב מעיים או ריאה--הרי זה פטור, מפני ששחט ברשות; אבל אם נמצא בעל מום, או שהייתה טריפה גלויה--הרי זה חייב חטאת, מפני שהיה לו לבדוק ואחר כך ישחוט. וכן כל כיוצא בזה.

Similarly, if one slaughters an animal for a Paschal sacrifice on the fourteenth of Nisan which fell on the Sabbath and afterwards, he discovered that the owners removed their connection from it, they died or became impure before it was slaughtered, or it became tereifah in a hidden place, e.g., its intestines or lungs were perforated, he is exempt, because he slaughtered it with license. If, however, it was discovered to be blemished or there was a readily apparent factor that caused it to be deemed tereifah, he is liable for a sin-offering, since he should have checked it before slaughtering. Similar laws apply in all analogous situations.