Is the covenant with Allah to abandon the forbidden invalidated if it later becomes clear that it is a matter of jurisprudential dispute?

If a person has made a vow or sworn an oath based on the prohibition of something, and then it becomes clear to him that it is permissible, he is not obligated to fulfill his vow. However, if there is a considerable difference of opinion among scholars regarding this matter, then the opinion supported by the strongest evidence should be followed. If the opinion of prohibition is stronger in evidence, the vow remains binding and must be fulfilled. But if the opinion of permissibility is stronger, the obligation to fulfill the vow is dropped.