Or that "40 days" is a linguistic construction meaning literally "a long freaking time". :P No, it's not just a few differences in the PoGP. It's basic errors that are quite evident - prolific, even - in the Bible. If every Christian sect read the Bible the same way, why would there be different sects? No, just because they all "believe the Bible" doesn't mean you can use "the Bible" as one node in your network.
The 40 days part is often considered symbolic, but the time period doesn't really matter.
In this comment thread, I gave the following idea, on the topic of a method by which one might judge the Book of Mormon from a rationalist perspective:
I would appreciate feedback on this idea, for an admittedly selfish reason: I am trying to instigate in myself a Crisis of Faith. So, here are the questions I pose to you: