As for another concern that Yates said she had over the Flynn-Kislyak conversations — the worry that Flynn’s lie to Vice President Mike Pence (that sanctions were not discussed on the call) would open Flynn up to possible blackmail — perhaps that is a legitimate concern, but why did it warrant FBI questioning of Flynn under the penalty of prosecution for making false statements? Certainly Yates could have warned the White House about that without interrogating Flynn at all.
Instead, it was the prospect of a Logan Act prosecution that led to the FBI interview, which then, when Flynn lied to investigators, led to his guilty plea on a false statements charge.
From today’s perspective, nearly a year later, it has become apparent that, farfetched as it might seem, the Logan Act made it possible for the Obama administration to go after Trump. The ancient law that no one has ever been prosecuted for violating was the Obama administration’s flimsy pretense for a criminal prosecution of the incoming Trump team.