I interpret your comment as you don't think I have a right to expect Christians to be genuine. It is true that anyone can call themself whatever they please. We know that from European History. It doesn't mean we must remain silent in the face of evil.
Expect away, but it still doesn't entitle you to the fulfillment of your expectations.
You have no idea what may have been said between Mel and Hutton Gibson privately on this subject. Neither do I. I believe I am not entitled to know it, though. Any more than Mel Gibson is entitled to know the status of relationships in my family.
As for being a genuine Christian, I don't see how public denouncement and repudiation to satisfy strangers can be reconciled with "Honor thy father and thy mother". I wouldn't do it myself, and I don't require it of Mel.