“What Is Done Is Done”

Lady Macbeth’s favorite line in Shakespeare’s play Macbeth is “What is done is done.” Was she correct in saying this after she and her husband had committed murder(s)? Surely, what is done is done, but that doesn’t mean it’s the end of the story. You still have to pay for your acts. Macbeth paid—he was killed by the King’s son. So, in one way she was right, but in another not—the act was still not paid for, so what had been done was not done yet.