How is Colson's position only tenable if all of us are shiny, happy people holding hands? If one position is "Altruism is the result of evolutionary development of the brain and is hardwired into the species" and the other position is "Altruism is a result of God's moral law" then an example of people ignoring that law does nothing to undermine his position.
It is precisely as much, or as little, an objection as an example of some people having defective wiring.
The problem is that Colson's position is just as weak as Pinker's (as Colson describes it): both fellows want to treat the topic of "animal behavior" as something neat and tidy, made up of discrete little elements that can be picked up and examined without reference to the whole package.
The problem is, of course, that behavior -- regardless of how it comes about -- is enormously complex, and it has to be so, because we live in a world where we have to be capable of responding to an extremely wide variety of situations. We have to be able to surive things that are unexpected -- so the ability to achieve a certain randomness in our responses would seem to be an essential capability.
It's not really valid for Colson to argue that Pinker is wrong, because real behavior is more complex than "hard-wiring" to a fixed cause/effect response. Pinker would no doubt admit as much. Colson's argument loses, because it is quite evident that behavior is partly heritable -- and anyway, you can't look at something like "altruism" in isolation from the larger package.