Bet it’s all about the oath.
I bet you're right.
She knows she's lying her ass off and inspite of the very, very dim chance any of her lies would trigger the largely toothless Senate to press charges through law enforcement, she doesn't want to take that chance. Even if they ever get her into the District of Corruption weeks from now, she will walk into the meeting room and tell them,
"I'm here to tell my story. But I won't be put under oath."
What would the wimpy senators do? We all know they would cave....