Is Cassuto Treif?

I was reading the Umberto Cassuto commentary on Genesis and thought to ask a local rabbi (with a mostly chareidi bent) about Cassuto. "How is he treated by the mainstream Orthodox world?", I asked. He gave a brief reply that Cassuto was well respected in the frum veldt. I then pulled out my copy and he asked to see it. After leafing through a few pages he responded "I changed my mind". Why?, I asked. "He discusses the Documentary Hypothesis." But, I replied, he attempts to debunk the DH and show the unified nature of Torah. "Yes, but he discusses the Documentary Hypothesis. He definitely isn't learned in yeshivah".

Now I can certainly understand an objection to Cassuto due to his constant references to Mesopotamian, Canaanite, and other myths of the Near East, claiming that these myths were well-known to the Jewish people, often as ancient poetic traditions. That doesn't jive well with those who believe that the Torah arose full-blown as a completely independent and revolutionary document, rather than an evolutionary one that incorporated traditions from earlier paganistic cultures. But Cassuto believed in a single, early author that - while incorporating earlier myths - treated such myths completely different and in keeping with the high ethical values of the people of Israel.

Nevertheless, what I found fascinating was that this rabbi's objections stemmed from the mere discussion of the DH. (I should have asked him about the Hertz Chumash!) I imagine that this attitude is one of "ignore it and it will go away". One could, however, make the case that it is the yeshiva world that has the most to gain by learning Cassuto since they are mostly ignorant of the assertions of the Documentary Hypothesis. It would give them at least a minimal amount of ammunition that they could muster if they are approached with cursory DH challenges. The double-edge sword, of course, is that they might then do a little more digging on their own and end up with their emunah seriously threatened...