I didn’t do anything wrong = I did not have sex with that woman.
In a courtroom situation (criminal case), a defendant does not have to testify since the government has the burden of proving guilt with independent evidence.
However, if the defendant does decide to testify, he or she can no longer invoke the 5th amendment right (against self-incrimination)and must answer questions posed by the prosecution.
So applying the same standard to today’s hearing, once Lerner gave her opening statement she, in my opinion, no longer had the right to invoke her 5th Amendment right.