The Rambam that follows is even more pointed than the first: (Shiggagos 13:17)
???? ??? ??? ?????, ????? ???? ????, ????? ???? ???? ???, ??? ?? ?? ?? ??? ???? ?? ????–??? ???? ?????? ?? ?????: ??? ??? ??????, ???? ?? ??? ???? ???? ?????? ????? ????; ??? ?????? ?????? ?? ?????, ???? ??? ??????–???? ???? ????, ????? ???? ?????.
If they (the people) knew Beis Din was wrong, then only the people are Chayiv (and are Mayzid!) as THEY SHOULD NOT HAVE FOLLOWED BEIS DIN!