Why did Flynn lie or not remember or not be clear with the 2 FBI guys?

My guess is because it was none of these FBI agents business what he said to Kisylak. If the by then known to be rogue, corrupt and leaking FBI was going to learn about what he said to Kisylak, it wasn't going to come from him. If someone else had already given them the information from illegal NSA unmasking transcripts, well, that would be a breach of national security and NSA rules and law by Obama, Susan Rice, Loretta Lynch and whomever, not Flynn.

As we can see as we've gotten to know these FBI agents including James Comey, these people are thugs, crooks, manipulators, deceivers and traitors who can't be trusted with any type of national security, foreign policy, foreign affairs or diplomatic content of any kind. I'm sure there's some good guys down the line somewhere, but even there, with the good guys in the FBI, they are not the people to have on demand access to national security, foreign policy, foreign affairs and diplomatic content. They don't understand it, it's not their background, they don't work with the person elected to have it and conduct it. They are removed from it, should stay removed, and there should be no further involvement by the FBI or DOJ for that matter on anything related to foreign policy.

It's like sending hospital security guards into an operating room to conduct inquisitions of brain surgeons to make sure they're doing it right and being truthful in the middle of a brain operation.

It's just that ludicrous and far more dangerous, because our relationship with Russia is the difference between war and peace and whether we or someone somewhere lives or dies, something General Flynn knows all too well.