Shaykh Bin Baz said, “If a person commits a mistake it should not be accepted, his mistake should be rejected, as [Imam] Malik said, “There is no one among us whose opinion may be rejected except the occupant of this grave”, meaning the Prophet (peace be upon him). Every scholar makes mistakes and gets things right, so what he gets right is to be accepted and what he gets wrong is to be ignored.
If he is one of those who follow the aqeedah of the Salafiyyah, but he makes some mistakes, the mistakes are to be rejected [and publicly refuted if the mistake is public], but this does not place him outside the pale of the aqeedah of Salafiyyah if he is known to be a follower of the Salaf but made some errors in interpretation of hadeeth or in some words that he spoke.
The mistakes should not be accepted and he should not be followed in this.
This applies to all the Imams. If Al-Shafi Abu Hanifah, Malik, Ahmad, Al-Thawri, Al-Awza`i, or any other scholar made a mistake [classical or contemporary scholar upon the Sunnah], what they got right should be accepted and what they got wrong should be ignored.
Mistakes are anything that go against the Shariah (Islamic legal) evidence, which is what Allah and His Messenger said. No one will be blamed for anything except a mistake that goes against the evidence. What we must do is follow the truth.
Allah (Exalted be He) says, “What Allâh gave as booty (Fai’) to His Messenger (Muhammad صلى الله عليه وسلم) from the people of the townships – it is for Allâh, His Messenger (Muhammad صلى الله عليه وسلم), the kindred (of Messenger Muhammad صلى الله عليه وسلم), the orphans, Al-Masâkin (the poor), and the wayfarer, in order that it may not become a fortune used by the rich among you. And whatsoever the Messenger (Muhammad صلى الله عليه وسلم) gives you, take it; and whatsoever he forbids you, abstain (from it).” [ 59:7]
Scholars unanimously agreed that any person’s opinion may be taken or left except the Messenger of Allah (peace be upon him).
[So] what we must do is follow what he brought and accept it and not reject anything that he brought, based on the ayah quoted above and other similar ayahs.
Also because Allah (Exalted be He) says, “(And) if you differ in anything amongst yourselves, refer it to Allâh and His Messenger (صلى الله عليه وسلم), if you believe in Allâh and in the Last Day. That is better and more suitable for final determination.” [Surah An-Nisa’ 4:59]
Ref: alifta.net – Fatwas of Ibn Baz, Volume 28
Posted by Abdul Kareem Ibn Ozzie