Actually, it wasn't that Lane was unaware. Or rather, he had a good guess as to what had happened in the Capital when he had been in the Eldenveil, even though he had been cut off from the outside world.
How? Because he had read through Blanc's plans and authorized them, of course!
But he still played dumb. Firstly, because plans were just plans, and no matter how good they were, there was always a chance they might not work out right. What he thought had happened and what Damien was talking about might have been two different things. Secondly (and most importantly)…
Damien didn't know anything about the secret organization or Lane's involvement in it, and it had to stay that way, at least for now. Thus, Lane couldn't betray that he knew anything, not in the slightest, so as not to raise any suspicion.
