Davis "wouldn't know what to do if you put the equipment in front of him", but he somehow manages to make a clear recording of a phone conversation. There are two ways I know of to do that, use a speaker phone and a microphone, or buy special equipment to feed the phone line through. The former is easy sure, but I don't think it would be at all clear. The latter would be impossible for a self-professed technophobe such as Davis.