Was the sharp argumentative defense of Islam and the imams correct, even though the other party persisted in discrediting Al-Bukhari and attempting to undermine Islam and faith?

It is not permissible to attend gatherings where forbidden acts, such as drinking alcohol, are taking place, unless there is a necessity. This is based on the Almighty’s saying: "And He has already revealed to you in the Book that when you hear the verses of Allah disbelieved in and ridiculed, do not sit with them until they enter into another conversation. Indeed, if you did, you would then be like them" (An-Nisa: 140). Therefore, one who is present at a forbidden act is like one who commits it. It is better to ask your brother to stop slandering the Shari'ah and direct argumentation, and instead resort to gentle admonition and guide him to sources that clarify the truth, because argumentation may increase hostility and engender doubts.