Hazrat Bukhari , Hazrat Muslim were all from the Ahle Hadeeth (Ashabul Hadith) group as opposed to Ahle Ray(Followers of personal opinions). This is the reason people get conflicting opinions on whether Bukhari was Shafi, Hanbali etc ,infact he was neither of them, not a Muqallid!. This fact is explained in detail in another related answer here.
Hazrat Bukhari wrote entire book opposing the Hanfi Madhab views on Rafuldayn called as Juz Al Rafuldayn.
Imagine an erudite scholar and Muhaddith of that level writing a book on a single and apparently small issue of whether to raise Hands or not, This speaks a lot of the kind of environment he was living in !
An English translation of the book Juz Al Rafuldayn has recently appeared here