Is it permissible to deny an act of harassment that occurred in the past, which the woman caused by filing a vengeful lawsuit, knowing that the current legal penalty in man-made law is estimated at one and a half years in prison, along with a feeling of injustice from the ruling?

If a woman forgives her right and pardons, she is not permitted to retract her forgiveness, for forfeited rights do not return. You are permitted to deny the act to escape punishment, because denying a sin to conceal it upon oneself is permissible, indeed obligatory, unless the person is openly defiant with it. It is preferable to use equivocation to avoid outright lying.