Both the followers of Abu Hanifa and the theological school of the Mutazila (many followers of Abu Hanifa’s school, in fact, subscribed to Mutazila theology) had used the Qur’an, the consensus of the Muslims and reason as criteria for determining if a Hadith was authentic or a forgery attributed to the Prophet. Its contents had to be tested against these criteria. If a Hadith contradicted any of them, it could not be true. It had to be a forgery regardless of who was claiming the Prophet had said it.
