The harsh reading given to Frieden's statements in that video is exactly what I mean by chickens running at axes.

He wasn't very clear there. But the CDC statements have been reasonably consistent and clear, especially in the face of the ridiculous questions they get from reporters. A softer reading is that transmission from an asymptomatic person who is later found to be infected is not believed to be possible at the time they are asymptomatic. Health workers with exposure should still, out of an abundance of cation, avoid contact with large groups of hard to trace people.