It is mentioned from Sufyan bin Uyaynah what indicates that he did not master it as precisely as these (narrators). Imam al-Shafi'i (may Allah have mercy on him), after narrating the hadith of al-Thaqafi from Ibn Uyaynah, said that Ibn Uyaynah was not certain whether the Prophet (peace and blessings be upon him) put the Ansar first for the oaths or the Jews. It would be said to him that in the hadith he put the Ansar first, and he would say: Then it is that, or something similar.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب القسامة / 16437