Furthermore it constitutes espionage. It would constitute a government wiretap without a warrant.
In a private business, your employer is free to record everything you do and everything you say. Those are the terms of your employment, and Comey was Trump's employee.
Can't you get even one law right? In DC (it's different in maryland where Linda Trip did it) The federal statute allows parties to the conversation to record the conversation.
Which means nobody can legally record Trump without being in the room. So when Trump cleared the room, the only people who could have recorded it are Trump and Comey, and Both said they didn't have tapes.