Well, of course she doesn't have to.
OTOH our so-called public servants are supposed to be accountable to the public, and so to the greatest degree possible, their official words and actions (e.g. while receiving testimony) should be publicly available. CSPAN does some of that, but the internet is everywhere.
So I suspect that she wanted to get out in front of this before some tabloid made a big deal of it. That's all.