How legal is that, recording someone without his knowledge or consent especially between a doctor and a patient?
Federal law states that one party can record a conversation that they are part of but California is a 2 consent state - meaning both parties have to consent. But who is to say that Michael did not consent? His talks with Rabbi Shmuley was consented.
Surely Estate can pursue a lawsuit if there are any recordings but whether they are legal or not would defend on many factors.