The one who practices tadlis in hadith, this is a specific question. Okay, tadlis in hadith is when someone narrates from someone he heard from, something he did not actually hear from him.
Something he did not hear from him in a way that could suggest he did, this is called tadlis in the science of hadith, but in any case.
He says: Why is it accepted from some who practice tadlis and not from others?
From others. In this issue, when the scholars discuss this matter, they look at his narrations in general.
They see how many times he omitted, and if he omitted, did he omit a weak narrator or a trustworthy one, and is his tadlis frequent or is it just using 'an'anah, when he says "from."
Does he always practice tadlis, or mostly, or only sometimes?
All of this goes back to rulings, and also to the leadership of this man and his scholarly status, and they look at whether he was followed.
Regarding this hadith, was he followed by others? If others followed him, then we are safe from his tadlis.
So all these issues are considered in the case of each of these six upon whom the knowledge of hadith revolves.
Qatada, Al-A'mash, and others, and Az-Zuhri—these six, Yahya ibn Abi Kathir focused on them.
So certainly Qatada ibn Di'ama is given much precedence over others, but even with this, if Qatada ibn Di'ama did not narrate from him, if someone other than Shu'bah narrated from him.
Some people only accept his 'an'anah if it is in the two Sahihs.
Outside the two Sahihs, some scholars do not accept the 'an'ana of Qatada.