I’ve also not seen the documentary, but the book is very good. I remember at least one peripheral comment referring to the “brothers of the Lord.” By peripheral, I mean that he is not arguing specifically to convince the reader that the “brothers of the Lord” are Joseph and Mary’s offspring and Jesus’ biological half-brothers. He simply mentions it in passing as an assumed fact (and his argument in no way rests upon it). Most people probably gloss over it. There may have been a few other such comments, but I can’t remember any offhand. I read the book ten years ago.
In any case, a simple preview of the documentary would show you if any such elements are present and need to be addressed. To me, as the reference is so tangential to the main point of an otherwise outstanding book, it’s well-worth recommending with the simple mention that he is not Catholic, and so adheres to some such non-Catholic notions.