First off, ask him to show you where it is in the Book of the Dead. I presume he’s never actually read the BoD, but picked up that info on some wacky website.
Secondly, Job is a story with a really basic plot; it asks the question of why good people suffer. The story itself is considerably old in terms of dating the Hebrew Bible, and it was probably told in ancient Israel over generations, most likely in different versions.
The closest parallel I could find was in a work called the “babylonian theodicy,” in which an innocent sufferer protests his anguish to the gods; they never respond, of course. In Job, God does respond. But anyways, that “suffering good-guy” theme is the only parallel, and it’s a pretty universal one at that. Conversely, Job as a unity is totally unique among Ancient Near East literature.
But, in regards to, “it’s really from the Book of the Dead,” your friend should give this lost peice of holy writings to the egyptologists immediately, because I’m sure they’d like to know about it.