This sort of argument seems to me to be more of a sort of ad hominem argument than any meaningful argument of morality. What is the claim? It starts out that you can't be good without religion and then, instead, makes a point that religion makes you less evil. Without even looking at the actual body counts or personal views of the supposed atheists, let's just assume that atheists have murdered and tortured more than Christians. What's the point? Christians have still murdered and tortured to a great degree. Are we supposed to look at this assumed discrepancy and conclude that God exists?
Perhaps the claim would then shift that simply the belief in God is beneficial as it tempers your immoral impulses. At this point, though, we are completely out of the realm of discussion of the existence of God. D'Souza, though, seemed to like this shifted arguing point during this panel discussion. At one point he says that religion, even if only wishful thinking, provides comfort at the loss of a loved one whereas atheism offers no consolation. Perhaps if Christianity didn't have attached with it the eternal torment of Hell, he would have an argument. I know that once I die, my atheist sister will be bereaved at my death as she knows she won't see me again. My Christian mother will be ever more so, as she will believe I am being tortured for all eternity in Hell for my unbelief.
Besides, if we are going to point to correlative data regarding the relative merits of a mere belief in God, then we have a rather difficult choice to make: should we choose no belief in God and murder more people, or should we choose to believe in the Christian God and rape more boys? I do not understand the argument.
(On the 95k year absence of God argument, I recommend Happy Jihad's House of Pancakes' post.)