I understand the culture in asSharq alAwsat is different. I know that Udai and Qusay had a very difficult time rebuking their father. I know that Bashar had a very difficult time rebuking his father. I know that any offspring of Yasser would have a difficult time rebuking him. I know all this.
The Gibson family is not like any of those families. Mel would not lightly rebuke his father for minor issues. He would respect him. The Holocaust Denial and Antisemitism are not minor issues. I find no Biblical excuse for a genuine Christian to hold his peace in the face of a such clear public sin by a parent. He should definitely go to him privately first, one on one. Should that fail, and the sin persist, he should go to him with other members of his Church (but we have a problem there, no ?). When the sin becomes so public we have another problem. In fact, the problem with 4% of the fathers in the Catholic Church of this generation was that too many people held their peace and kept if quite private.
Now Hutton's sin is no where as notorious as that of that minority of fathers, yet who knows if someone had rebuked them earlier what lives might have been spared ? Open rebuke is better than secret love. Open sin should be rebuked, both for the sinner and those who are affected and influenced by such sin. Hutton Gibson has clearly sinned and no one is doing him any favors by not addressing it.
I believe that upwards of 6 million Jews were murdered by the Nazis. But if someone believes it were 2 million or 4 million-- isn't that quite enough to demonstrate the Nazis were evil bastards who deserve to burn in Hell?
And I don't understand why you, a clearly intelligent guy, needs to set up a straw man like the murderous Tikritis to compare to Gibson and his father. The Baathists killed people I knew. You know it's different but you bring it up anyway.
You say there is no biblical excuse for a Christian to hold his peace on public sin. While I'm not a Christian, and I'm not looking for excuses for anybody, I can give you a very old commandment that goes something like this...
HONOR THY FATHER AND THY MOTHER
As a Muslim, here's the way I look at it: Mohammed said that even if your parents are pagans who curse you and prevent you from practicing your faith, do not respond with unkindness. I think it goes like this...
"Speak to them not like the braying of an ass, but Guide them to righteousness, but gently, as Heaven rests beneath the feet of your mother and father"