Horayot 7B

אמר רב פפא: כגון שהיו מופלין שניהן.

Rav Pappa says: The reference is to a case where both the anointed priest and the court, i.e., the judges, were distinguished Torah scholars with the authority to issue rulings.

סבר אביי למימר: חטא בפני עצמו ועשה בפני עצמו היכי דמי? דיתבי בשני מקומות וקא מורו בתרי איסורי, אמר ליה רבא: אטו שני מקומות גורמין? אלא אפילו יתבי בחד מקום, וכיון דקא מורו בתרי איסורי ⁠– חטא בפני עצמו הוא.

§ Abaye thought to say that with regard to the cases in the Mishnah: If the anointed priest sinned by himself and performed a transgression by himself, what are the circumstances? It is a case where the priest and the court were convened in two different places and issuing rulings with regard to two different prohibitions. Rava said to Abaye: Is that to say that the fact that there are two places determines that he sinned by himself? Rather, it is even in a case where the High Priest and the court are convened in one place. But since they are issuing rulings with regard to two different prohibitions, it is a case where the anointed priest sinned by himself.

פשיטא: הוא בחלב והן בעבודה זרה ⁠– חטא בפני עצמו הוא, דהא חלוקין בטעמייהו, וחלוקין בקרבנות. דהוא בפר, והן בפר ושעיר ⁠– דהא קא מייתו הני שעיר, והוא לא מייתי. וכל שכן הוא בעבודה זרה והן בחלב, דחלוקין בקרבנותיהן [לגמרי] ⁠– דהוא שעירה, ואינהו פר,

The Talmud continues: It is obvious that in a case where the anointed priest issued a ruling with regard to forbidden fat and the judges issued a ruling with regard to idol worship, it is a case where the anointed priest sinned by himself. As in this case the rulings are distinct in terms of their reasons, as each ruling is based on a different Torah source, and they are also distinct in terms of their offerings, since the priest achieves atonement with a bull as a sin-offering, and the judges achieve atonement with a bull and a goat as a sin-offering for unwitting idol worship, as these judges bring a goat and the priest does not bring a goat. And all the more so in a case where the anointed priest issued a ruling with regard to idol worship and the judges issued a ruling with regard to forbidden fat, it is a case where the anointed priest sinned by himself, as these rulings are totally distinct in terms of their offerings, since the priest brings a female goat as a sin-offering and the judges bring a bull.