He didn't do this to help Lissy Lock. He did it entirely for Skye Turner.
Miss Turner was the one in fault in that incident. He felt very guilty at the time, feeling as if he had let Lissy down.
Now, he couldn't stand idly by and watch Miss Turner going off-track and making more and more mistakes.
As Lissy told him, some things just shouldn't be done.
Miss Turner couldn't go on making mistakes, she needed to turn back now.
If Nova York clung to it as a means to blackmail Miss Turner, then the best approach was to ensure this couldn't be used as Nova's trump card anymore.
What Lissy was doing now was just that.
When Lissy revealed the full truth to Mr. Fame about how Miss Turner pushed her down the stairs and gave him that voice recorder, this matter would no longer remain a secret.
Miss Turner wouldn't have to live in constant fear about when Nova would blackmail her with this incident.
Without a trump card or bargaining chip, Nova would not be able to control Miss Turner.
