Tosefta su Levitico 7:18

[If] a beit din ruled at the conclusion of the Sabbath [that the sun had set, thus permitting labor], and then later the sun was seen shining [as may occur, e.g., on a cloudy day], this is not an erroneous ruling but merely a mistake (Yev. 92a:2). [If] a beit din ruled to uproot an entire principle, [such as if] they said, "There is no blood (i.e., laws concerning the blood of a sacrificial animal) in the Torah," "There is no fat (i.e., laws concerning the fats of a sacrificial animal) in the Torah," "There is no piggul (Lev. 7:18) in the Torah," behold, they are exempt (Hor. 1:3). [If] they ruled to nullify part and uphold part, behold, they are liable. How so? [If] they said, "There is blood [in the Torah] but there is no obligation, except as to the blood of a peace offering." [Or if they said,] "There is fat in the Torah but there is no obligation except as to the blood of a peach offering." [Or if they said,] "There is piggul in the Torah but there is no obligation except as to piggul of a peace offering." Behold, [in these cases,] they are liable, as it is said elsewhere (Deut. 17:8, see below), "matter." What does "matter" mean? As is said elsewhere (see Midrash Tehillim 105:1), of part of it, but not all of it. You say, a "matter" is part of it, but not all of it, or is it only all of it? The Torah teaches (Deut. 17:8), "[When any matter is too baffling for you, in justice,] between blood and blood," and not "all the blood" -- "between judgment and judgment," and not "every judgment" -- "between plague and plague," and not "every plague" -- thus, there is no need to say [in accordance] with the first version, but rather [in accordance] with the last version. [Just] as it says here, "matter," and it says elsewhere, "matter," what is "matter," so too it says elsewhere "part of it," but not "all of it." Rabbi Shimon ben Eliezer says in the name of Rabbi Meir, "If six sinned and they are the majority, or seven, even if they are not the majority, behold, they are liable."