Public criticism and rebuttal of someone who openly makes errors relating to the religion of al-Islam does need to be advised privately, and this is well established from the action and understanding of the Salaf, and inshaallah I will bring some proofs relating to this issue in this article.
It should be noted that privately advising a sinner about his sin is a completely different issue, and the two should not be confused.
In the Quran, Allah (swt) has “publicly” corrected the Prophet, peace and blessings of Allah be upon him, on a few occasions, including the interaction of the Prophet with the blind companion, as found in Sura Abasa, regarding Abdullah ibn Umm Maktum, and this is of the greatest of proofs that does not require a second,
that is if someone makes a mistake concerningthe religionof Allah, public criticism is permissible without prior, private warning.
Umar (ra) was publically critised on multiple accounts,
1. Why he had two garments
2. Woman refutes Umar (ra) regarding mahr
3. His statement if I go astray, “we will straighten you with our swords”
Many other examples can be found in the seerah
The salaf also had some words regarding criticism,
Muhammad Ibn Bandār al-Jurjānī said to Imām Ahmad ibn Hanbal (rahimahullāh), “It is hard upon me to say: ‘So-and-so is such-and-such and so-and-so is such-and-such’. So Imām Ahmad replied, ‘If you remain silent and I remain silent, how will the ignorant person know what is correct and from what is false?’“
(Majmū al-Fatāwā 28/231, Sharh ʿilal al-Tirmidhī 1/350)
Imām Ahmad was asked about Husayn al-Karabīsī, he responded, “He is a mubtadiʿ (innovator).” On another occasion, he (rahimahullāh) said, “Beware of Husayn al-Karabīsī. Do not talk to him, and do not talk to the one who talks to him.” ― he said it four of five times. (Tārīkh Baghdād 8/65.)
The science of Al-Jarh wat-Ta’dīl, is well established in the shariah,
This is especially true regarding those who narrated Hadith, and those who were people of innovation and of thise who publically made mistakes
Imam ahmed himself was quoted in saying,
Imaam Ahmad, may Allaah have mercy on him:
1. Al-Marwadhee (rahimahullaah) said: “Abu ‘Abdillaah (Ahmad Ibn Hanbal) once mentioned Haarith al-Muhaasibee and said: ‘Haarith is the source of all this affliction – meaning the innovations of the views of Jahm. There is no calamity except for Haarith.’” Bahr-ud-Dam (pg. 99)
2. Habeeb Ibn Abee Hilaal: Ahmad said of him: “He is rejected.” Bahr-ud-Dam(pg. 105)
3. Habeeb Ibn Jahdar: Ahmad declared him a liar. Bahr-ud-Dam (pg. 109)
4. Al-Hasan Ibn Dhakwaan: Ahmad said of him: “His ahaadeeth are forged” and in one report, he said: “He is of no significance.” Bahr-ud-Dam (pg. 114)
5. Khaalid Ibn Yazeed Ibn ‘Abd-ir-Rahmaan Al-Hamdaanee: Ahmad said: “He is nothing.” Bahr-ud-Dam (pg. 114)
Bukhari and An Nasaee did the same. They mentioned people by name, their faults publically, and did not restrict it to private advising.
So if an Alim, Shaykh, Ustadth, or Daee and anyone else speaking in the name of Islam openly and publicly makes errors, correcting the error publicly is permissible as this allows the correction of this error that would have misguided or mislead the community.
None of us are free from mistakes, errors, and shortcomings, but the preservation of that which is authentic and correct far outweighs the image of the individual who has made the error
And there should be no favouritism regarding that.
And Allah knows best.