The only time lying to an FBI official (or anyone else) should be a crime is if you’ve officially *sworn* to tell the truth...as happens in a courtroom.
Misremembering and lying are not the same thing.
They way they set you up for a perjury trap is the first time they contact you they make it relaxed and informal, you’re doing them a favor by having a little chat with them to help them out.
The next time they contact you you’re taken into a room and grilled.
Any discrepancies between the first time you talked to them and the second time is “lying to the FBI.”
Lying to the “FIB”.
So what is the punishment due the FIBbers?