Animal Certainty + Ethics

Regarding my previous post on Wittgenstein's so-called animal certainty: What about situations in which we fail to agree? Every non-philosopher, non-amputee/casualty agrees that he has two hands. He may even agree in a non-propositional way. Granted.

The next step: Thou shalt not murder. There will be contexts in which it makes sense to murder (exactly just as there are contexts in which, "I know I have two hands" makes sense). When someone steps on your toe--you fail to murder someone. Animal certainty. What about this situation? I remember reading about it roughly during Katrina and thinking, "that seems right." Well, what about people that think it's wrong?

The animal certainty model of ethics cannot cope with this. Can it?