What does the author mean by describing Abd al-Rahman Abd Allah ibn Dinar as weak, and does that affect his narration?

Abd al-Rahman ibn Abd Allah ibn Dinar al-Adawi, whose narrations were transmitted by al-Bukhari and others. Scholars have differed concerning him, some weakening him, others authenticating him, and others taking a middle ground, such as al-Albani who deemed his hadith hasan (good). Al-Bukhari and Muslim selectively transmit from individuals about whom there has been criticism, especially if they are among their teachers, or they include their narrations in supporting evidence (shawahid) and follow-ups (mutabaat), not as primary narrations for the chapter's foundation. Al-Bukhari may transmit from a narrator about whom there is criticism because he considers him trustworthy and believes the criticism does not harm him. Shaykh Abu Abd al-Rahman al-Azim Abadi mentioned in his book "Awn al-Mabud" that there is weakness in the isnad of Abd al-Rahman ibn Abd Allah ibn Dinar al-Madani, and scholars have differed concerning authenticating or deeming his hadith defective due to him.