I feel that claiming things were said without recorded evidence would lead to a "he said she said" type situation. Especially when the call was never made from a known number, but rather a "blocked number." How could one be sure someone even made the call instead of the other side fabricating evidence? Would one's sworn testimony to the content be enough? What if the other side lied? It's scary that someone can lie about a fake phone conversation and have it admitted into evidence.