He became convinced that he was a scholar capable of independent reasoning (mujtahid). Henceforth he began to answer each and every scholar great and small, past and recent, until he went all the way back to `Umar (r) and faulted him in some matter. This reached the ears of the Shaykh Ibrahim al-Raqi who reprimanded him. Shaykh........ went to see him, apologized, and asked for forgiveness. He also spoke against `Ali (r) and said: "He made mistakes in seventeen different matters."
I dont want to mention Shaykh...... but this is something you can ask the learned people and clarify. I'm sure they would be able to fill the gap if there is any truth in it. And if there is, then SubhanAllah.