In Bible studies, especially the Evangelical ones, many love the principle of "Speak out your opinion, nobody is wrong".
I am not so. I would point: This one is wrong, that is right, this person is right, wrong, etc.
I wouldn't even consider covering someone's erroneous statements. One must be responsible for one's speech.
Bible study is teaching when there's a teacher present. Not discussion and certainly not a place to bring false principles and false doctrines.
Questions and doubts are always welcome, but one shouldn't be defensive when one's false doctrine is judged. Who can judge? All servants of God, followers of Christ.