To what extent is a person responsible for committing forbidden acts based on a scholar's fatwa, and when is he excused or held accountable in this situation?

The common person is excused for following someone else if they believe that person is among the people of knowledge and ijtihad (independent reasoning), and they assume that person has reached the correct conclusion on the matter, and they did not follow them out of whim or bigotry. As for the scholar, they are rewarded between one and two rewards if they exert effort with the intention of reaching the truth and expend their utmost. The saying, "Whoever follows a scholar will meet Allah in safety," is not absolute. The hadith: "Whoever is given a fatwa without knowledge, their sin is upon the one who gave the fatwa," applies to the ignorant person who asked a scholar and was given a false answer, and acted upon it without knowing its falsity. In this case, the sin is upon the mufti if they fell short in their ijtihad. It is incumbent to restrain and discipline the reckless mufti.