Well, so far, the only evidence we have the Gibson has repented is a statement from a publicist.
God had enough to send His only Son to take Mel's punishment upon the cross.
He calls us to accept that same mercy and grace for all of our sins. It's impossible to merit His forgiveness. The only way to receive clean consciences: to trust in His grace given in Christ.
And God calls us to stop bringing up other people's sins when they have repented.