We previously mentioned that one who knows that the Sanhedrin is wrong is not allowed to follow their decision. This is based on the Gemara in Horayos (2b). This idea is even more explicit in the Yerushalmi (1:1) which states clearly that if the Sanhedrin tells you that “your right is left” (or vice versa), one should not listen to them. Additionally, the language of the Sifrei is “if it appears to you that they have erred, then you should follow them”, which tells us that if we are sure that they have erred, then we should not follow them...