You have it a little wrong....
FIB does interviews with 2 agents. One asking the questions and interacting with suspect/witness/victim. The other takes notes. And the interviews are not recorded, like EVERY OTHER LAW ENFORCEMENT AGENCY IN THE UNITED STATES does. I’ve been out of law enforcement for a while. But nowadays, I doubt you could get a conviction on anything, unless there’s video or audio evidence. Folks don’t trust law enforcement anymore.
So, the only record of what was said is what is in the agents report. Nothing more. If the FIB had to operate under the same rules as local cops and detectives, most of them would find a new line of work or be run out of the job. A good street cop or detective could work circles around them with 1/3 the resources.
So, if the interviewee says that he told the agent that the sky was blue, the agent can say that he said the sky was green. And there’s no way to know who is telling the truth.
Hence, how folks think the FIB can make stuff up, out of thin air.
However, in this case, even their own paperwork showed that they didn’t think that Flynn lied, so somewhere in between, someone pulled some real dirty shit.
I would love to watch the reaction of the FBI if, when they go to “just ask a few questions” someone would say sure, you don’t mind if I record this interview do you?