Julianna G (Duck with a gun)

A friend of mine was hurt very badly in a divorce when he found out his wife was cheating on him while he was deployed in Iraq (and starring in her own porn site). She met him with divorce papers when he got home, and managed to get the divorce moved to a state very favorable toward mothers and unfavorable toward fathers. In short, he was essentially told by the Colorado courts he was an unfit parent because of his military service and was denied custody. He was supposed to be allowed to visit his son whenever he was in the area, but every time he tried, she refused to let him see him. He has records of his many, many attempts to see him, as well as pay records showing he was paying the child support and alimony.

She was killed in a car accident earlier this week, and was apparently lying to her mother about receiving child support this whole time, so now the grandmother is trying to get custody by lying to the judge and saying he's never shown any interest in his son. Because the mother kept him away from his son, the courts are saying the grandmother would psychologically be a better person to put his son with (since she's had contact with him) even though she intends to continue the trend of keeping a child from his father.

Is it unChristian to feel like someone like this isn't making the world a worse place for having died?

It seems that there are many who call themselves Christians (I don't care what denomination or how you define Christianity. Self-profession counts here) who spend a great deal of time trying to tear down the religious beliefs of others, and in some cases engage in name-calling, spreading untruths about others' beliefs, etc. What biblical passages would you say justify treating others like this? How do these attitudes fit with the teachings of Christ?