If
a single witness says to a person, “Your ox was sodomized,” and it is
therefore unfit to be a sacrifice, and that person remains silent, the
witness is believed.
King Yannai was incited by Elazar Ben
Po'ira against the sages of Israel. Yannai wore the golden plate of the
High Priest, and one sage protested that Yannai was an unfit Kohen.
Elazar suggested to kill all sages. But what of the Torah? - Here it is
in the corner, anybody who wants can learn! Yannai executed the sages.
Why was Yannai fit? The witnesses to his unfitness were later
established as false witnesses.