Abu Hatim al-Razi: He saw the Prophet (peace and blessings of Allah be upon him) from the narration of al-Thawri
Abu Zur'ah al-Razi: He considered his companionship to be authentic
Abu Isa al-Tirmidhi: His companionship is not authentic
Ahmad ibn Hanbal: Al-Hakam does not have companionship
Ibrahim ibn Ishaq al-Harbi: He considered his companionship to be authentic
Ibn Hajar al-'Asqalani: He had companionship, but his narration is unreliable, his companionship is disputed
Al-Dhahabi: He had companionship, his narration is unreliable, there are different opinions about him
Sufyan ibn 'Uyaynah: His companionship is not authentic
Muhammad ibn Isma'il al-Bukhari: Some of the children of al-Hakam ibn Sufyan said: He did not meet the Prophet (peace and blessings of Allah be upon him), al-Hakam does not have companionship
Authors of Tahrir Taqrib al-Tahdhib: His companionship is not authentic, he has one weak and very unreliable Hadith in the Six Books