Saletan just equated Tiller's killer with Tiller himself--look at the parallel construction.

Saletan is wrong to do this. The two are nothing alike. One was a physician engaged in the practice of medicine. The other was a terrorist. Claiming they're equivalent is intellectually dishonest and ethically dangerous.

I would argue that the article was actually designed to make us think about this moral equivalency, and reject it - the article is in fact making the point you are making.

I agree with the original poster. I didn't see any indication that we are supposed to reject this equivalence, and I find it disgusting. Perhaps you are reading that into it because you reject the equivalence?