I don't actually see a legitimate rebuttal to argument #2 (passing the tax on). In the article, the author simply says "...no, because land is special in that it is scarce and nobody can make any more of it." It's not clear to me that this is an argument against the proposition that the tax will be passed on. Indeed, you could argue that it makes it more likely, since the scarcity of land gives the landowner more economic leverage (ie, if you don't like our rents, go try to buy your own land). There may very well be a sound economic argument that explains why the tax wouldn't just raise rents, but I don't see it in this article.