All perfect praise be to Allah, The Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.
Ibn Hibbaan mentioned in his book Al-Majrooheen:
“Yahya ibn ‘Abdullah ibn Maahaan narrated to us from Ibn ‘Uyaynah that he said, ‘I narrated a hadeeth from the Prophet to Abu Haneefah and he said, ‘Pee on this…’”
He also mentioned other stories indicating that Imaam Abu Haneefah rejected some ahaadeeth and that he once said about one hadeeth, ‘It is a myth,’ and at another time said, ‘This is filth,’ and so on. It is for this reason and others that a group among the Salaf (righteous predecessors) criticized Imaam Abu Haneefah, while others praised him.
We believe that Imaam Abu Haneefah did not reject a hadeeth from the Prophet that was proven authentic to him.
Dr. Muhammad Sa’eed Al-Qahtaani, while reviewing Kitaab As-Sunnah authored by ‘Abdullah, the son of Imaam Ahmad ibn Hanbal, spoke about these criticisms against Abu Haneefah, and he stated that more than 50% of them [these criticisms] are not confirmed to be authentically attributed to those who said them. It was reported from Ibn ‘Abdul-Barr that those who authenticated Abu Haneefah and praised him are more than those who criticized him.
It was reported that Shaykh Ibn Taymiyyah said, “If anyone thinks that Abu Haneefah and other Muslim scholars deliberately rejected an authentic hadeeth, due to analogy or else, then he indeed said something wrong about them, and he spoke either because of assumption or because of following personal inclination."
Allah knows best.