Biography: Imam Bukhari
Imam Bukhari was a Mujtahid
Muhammad Ashiq Ilahi (Hanafi):

Statement by Muhammad Ashiq Ilahi Bulandshahri Hanafi (in the Biography of Muhammad Zakariya Hanafi):

“In my view, the correct opinion is that Imam Bukhari (may Allah have mercy on him) was firmly a Mujtahid (independent jurist). If he is to be considered a Muqallid (follower of a school), then he would not be like us — that whatever the Imam said, we simply acted upon it.” [Sawaneh ‘Umri Muhammad Zakariya, p. 334]