Though there's only a moment where he's thrown, the moment was there regardless. He makes a quiet sound of amused acknowledgment, but doesn't try to extend the moment; Jason just watches her go, and directs his smile at the floor as if that would hide it. If he feels more at ease with Olivia, that itself should be a warning to stay more on guard. He has to remember it's an illusion.

It's a nice one, though.