The issue of how we deal with the mistakes of ulema is a tricky and sensitive question. Over the years my limited experiences have shown me that it doesn’t matter what side of the taqlid debate you are on, once people build up respect for a scholar it becomes very difficult for them to accept that the person may have made a major mistake.
The issue is a difficult one as there are a number of factors which need to be taken in to consideration. Legitimate differences of opinion is one (note: legitimate, this is a blog post by itself), having a good opinion of others or lack of detailed knowledge are some of the factors at play.
One of the best things I have heard in this regard is that criticism of ulema is accepted when coming from a scholar of a similar level. Thus any criticisms of a particular aspect of Imam X’s work should only be given attention when someone of a similar stature is pointing out the mistakes. Similarly one of the recent teachers of the Sawlatiyyah school in Makkah when discussing an issue reiterated to me, “I always emphasize, weigh up what is being said and not who is saying it”. This approach also has its merits but perhaps needs careful application to prevent it being misapplied.
Much more could be written on this, I came across the following from Imam al-Munawi in his Fayd al-Qadir (1/242). The hadith he is commenting contains some weakness in its chain, but still worth some attention, from scholars, those studying and those following scholars.
“Beware of the slip ups of a scholar” Meaning be warned of of following him in it such as…his taking that which is doubtful from the wealth of the ruler and others; his visiting the ruler; regularly meeting him; aiding him by leaving the forbidding (of evil); violating peoples honour; verbally abusing others in debates; belittling people and raising himself above them; busying himself with knowledges from which he does not intend except attaining status.
Likewise his carelessness in giving legal verdicts and ijazah and his shortcoming in expending his efforts and giving due attention regarding that which he is asked about; his rushing to answer immediately with his pen or tongue and his generalising in a place which requires detail and explanation.
The world follows the scholar in these sins, the scholar dies but his evil remains spread out across the world. It is therefore said that, “his slip up will cause him to be rotated in the fire” Meaning his being turned upside down on his head…due to the countless evils due to the creation following him resulting from his slip ups. It was due to this that some of the Sufis said, ‘If a scholar slips up the entire world slips up due to his mistake’…
When he turned the creation away from guidance due to his slip up, Allah Taala will turn him over in the fire as a punishment…
If you say: How can the slip up of a scholar enter him in to the fire when he is rewarded for ijtihad even if he is wrong? it was due to this that Ibn al-Mubarak said, ‘How many a good person with pious acts made a blatant mistake and slips up, which he should not be followed in.’
I say: A slip up or mistake sometimes occur due to a lack of striving (ijtihad), the one who does this is not rewarded rather is punished.
Sometimes it occurs with a full striving (ijtihad) however a mistake occurs by the declaring lawful the prohibited, prohibiting the unlawful or leaving a wajib due to an interpretation…this person however is rewarded for his striving (ijtihad) and not punished for his slip up.”