Christian scholars simply don't get the in-depth exposure to the Rabbinic literature that they should have. Just look at the various ways so many (ab)use the word midrash as an example. Christian interaction with the Rabbinic literature, the documents of the Oral Torah, seems always to have been according to a Christian agenda, disallowing the documents to speak for themselves, often at best serving as simply a mine for interesting tidbits stripped of context, used in Christian historical or exegetical programs. The Oral Torah must be understood on its own terms, root and branch, and only then can a fruitful comparison begin to be attempted. This is a project only now in its beginnings.
Update: Jacob Neusner has contacted me and kindly given me the following advice:
If you want to know the books of mine that I most value, I would say JUDAISM: THE EVIDENCE OF THE MISHNAH, THE TRANSFORMATION OF JIUDAISM: FROM PHILOSOPHY TO RELIGION; and THEOLOGY OF THE ORAL TORAH. These cover my work in literature, history, and theology.