The hadiths in al-Bukhari vary in their degree of authenticity, due to the presence of some narrators who are criticized regarding their memorization.

The Shaykh : ... Then I must mention what I recalled recently: there are hadiths in al-Bukhari that have weakness due to some of the narrators, such as Abu Bakr ibn 'Iyash. In my knowledge and critique, the biography of this Abu Bakr concludes that his hadith is hasan (good). This fact is also very apparent to researchers, namely that the authentic hadiths in Sahih al-Bukhari are not equal in their degree of authenticity; rather, they vary completely to the extent that some descend from the rank of sahih (authentic) to the rank of hasan (good), and some even descend from the rank of hasan in itself to the rank of hasan due to external factors. There are narrators who have been accused of ikhtilat (confusion), and there are narrators who have been accused of tadlis (concealment of a defect in a chain). So when a hadith scholar and huffaz (memorizer) like Ibn Hajar al-'Asqalani stands before such narrators in Sahih al-Bukhari, he finds no excuse for them except to say that, for example, regarding one who is known to be confused like Abu Ishaq al-Sabi'i, whose known name is 'Amr ibn 'Abd Allah, he carries the narration of Imam al-Bukhari from this confused narrator on the basis that it was established for him through another path that he narrated it in a state before his confusion. But because the chain that was established for him showing that he narrated it in a state free from confusion did not meet his conditions, he did not narrate it in his Sahih. Similarly, when he stands before some of those accused of tadlis, like Qatadah for example and others like him, and he narrates from them using the 'an (from) formula, he says that this is carried on the basis that al-Bukhari established the hadith for him in some other narrations where he explicitly stated the narration (takhrij). Sometimes he actually finds, either in another narration in Sahih al-Bukhari or outside the Sahih, that he explicitly stated the narration. My point in this is that there are narrators in whom there is a defect, in whom there is a criticism, and yet al-Bukhari narrated from them. So if a researcher searches and does not find for such narrations—whether for the confused one that it was established that he narrated the hadith before the confusion, or for the one who conceals defects that he explicitly stated the narration—then at that time, it is not permissible for him to say that the hadith is sahih (authentic) except by following Imam al-Bukhari in taqlid (following a scholar without knowing his evidence) and submission to him. Otherwise, in the hadith critique indicated by the rules of hadith science, there is no way to avoid saying that this chain is defective. This distinction also applies to the two Sahihs, especially since we read in the biographies of men that "so-and-so narrated for al-Bukhari with the addition of another" or "with a supporting chain" or something similar. All of this indicates that what is in al-Bukhari and what is in Muslim are not of the same degree of authenticity. So when it is said "sahih (authentic)," that is a general statement. In detail, there is what is hasan (good) and not sahih (authentic). Then this hasan (good) is divided into two categories: hasan in itself and hasan due to external factors. These are facts that scholars know and do not doubt at all. But because the majority of Muslims turned away from engaging in this science, it was naturally not possible for them except to rely on that word: "What the two Sahihs contain, the community accepted." This is a sound statement, as I said earlier, in general terms and not in detail. Other than that, the time is almost becoming eleven o'clock.