You also don't fight dirty when it comes to your kids.
The very fact that we have to go to court to duke it out is dirty, IMHO. Yes, the law is there maintain societal peace and relative fairness. But sometimes, certain aspects of the law forces the worst out of us.
For example, I may be forced to contest in keep our son here in CA, while my wife will do the same to challenge that. Every trick in the book will be used (be they good or bad) and someone is going to be the "winner". My heart and soul aches doing it.
My point is even if you try to keep the "fight" clean outside of the legal system, the legal system forces you to fight dirty to protect yourself. I'm not a lawyer, obviously, but I'm a God-fearing human and this just doesn't sit right.