What is the ruling on the debates conducted by Ahmed Deedat with Jews and Christians?

Shaykh Ahmad Deedat, may Allah Almighty have mercy on him, engaged in famous debates with Christian scholars and priests, in which he refuted them. These debates were published and had a significant impact in the Western world, leading the Church and Western universities to dedicate sections in their libraries to his debates and books for study. His most famous debate was with Jimmy Swaggart, who had slandered the Messenger of Allah, peace and blessings be upon him, but then apologized and retracted his slanders at the end of the debate. We ask Allah for mercy and forgiveness for Shaykh Deedat.