Mawlānā Shabbīr Ahmad `Uthmānī رحمه الله تعالي mentions:
Those scholars who have used harsh words against Imām Abū Hanīfah رحمه الله تعالي , we should only think good regarding them as a believer is jealous (ghayyūr) and sincere in his intentions. When he is informed of something which seems to be contradicting the sunnah and destroying dīn (even though in reality it is not so) then his jealousy for dīn overtakes him causing him to get angry for the pleasure of Allāh Ta`ālā. Thus, resulting in him using harsh words in defence of the dīn.
An example of this is Imām Muslim رحمه الله تعالي using strong words against Imām Bukhārī رحمه الله تعالي in his muqaddimah. Most commentators have preferred the view of Imām Bukhārī رحمه الله تعالي but they did not criticise Imām Muslim رحمه الله تعالي for using harsh words. (Fathul Mulhim 1/73)
Extracted from Ask Imam fatwa #18609
A lesson and reminder for us.
Our scholars and mashaykh do the same regarding those who reviled their akabir. Even those who went to the extent of making corrupt allegation of kufr against them.