Imagine you have a drug empire and the police are trying to take you down. Now if the cops flip someone in your crew, then they can be considered a "confidential informant." Then everything they gather will be admissable in court.
Now if the police hire another person to infiltrate the police who is not an undercover officer, ( which has to be done with warrants) and then that person brings information, that is called a spy. The difference is that everything they gathered would no longer be admissable in court, and would therefore be considered " entrapment." Any two bit lawyer could have the case thrown out in a matter of minutes.
I really wonder where they were going to go with this had the spy actually found anything out.
Hillary was supposed to have won - so it would never have come out.
Even now they are doing the best they can to cover it up.
They were so certain they could win that they didn't even bother trying to cover up their crimes. That's the key how the whole operation is going to keep tumbling down.