If al-Bukhari (may Allah have mercy on him) says in a hadith that a narrator did not meet another narrator, does that mean the hadith is not authentic, and do we accept this without investigating the hadith?

The Shaykh : The point is that al-Bukhari does not accept a report from a narrator regarding someone of his own time unless he knows that he heard from him in some of the narrations. He says of this person known as al-Nafs al-Zakiyyah that it is not known that he met that Tabi'i who narrated the hadith from the Messenger of Allah (peace and blessings be upon him). He says, "I refrain from accepting this hadith," and in similar cases he says, "It is not corroborated." People who have no knowledge of the principles and rules come and say, "Imam al-Bukhari weakened this hadith." We say, "You are correct." When al-Bukhari weakened a hadith, he based his weakening on a methodology of his own, which is that "contemporaneity is not sufficient to prove meeting," unless there is a text such as "I heard" or "He narrated to me" or similar expressions. Imam Muslim and the majority of scholars hold that this methodology involves restriction and the weakening of hadiths by the hundreds, indeed by the thousands. Indeed, Imam Muslim, in the introduction to his Sahih, indicates that Imam al-Bukhari himself is unable to apply this methodology to the hadiths in his Sahih, let alone the hadiths he narrated outside his "Sahih." Yes.