Ribofunk stream of thought

In Little Worker Di Filippo introduces a splice that acts independently on different parts of its DNA. This leads to the murder of Mister Michael's wife. I am having trouble understanding the logic behind this. A dog wouldn't kill it's owner's wife, a human wouldn't kill his friend's wife, and a wolverine wouldn't consciously decipher between the two. This ability to shift processes strikes me as impossible, particularly if there is so little "human" in such a being.