A few dapin ago, R’Chanina suggested that the Kohanim observed Rabbinic ordinances, which struck this reader as unlikely in actuality but a calculated move in suggesting rabbinic authority over the Temple priests. Today Rav suggests that the Kohanim performed the Temple service incorrectly. Politics is playing out here . . . and still no further mention of chametz.
Daf 340 (Pesachim 17a-17b)
Rav asserts that the Kohanim held incorrectly regarding the degree of contamination acquired and conferred by liquids and “that is why it is written that all their handiwork and what they offer in the Temple is tamei.” This is disputed by others.
A ruling by R’Yehudah may or may not have been retracted, but even if it was, the gemara still needs to determine whether the retraction was complete or only partial.