I never knew any of that either, until I quit going to the KH.
Here's a book to suggest he read: Forged: Writing in the Name of God--Why the Bible's Authors are Not Who We Think They Are, by Bart Ehrman. I understand that not everyone agrees with all of Mr. Ehrman's points, but this book is sure an eye opener.
Available on Amazon and Kindle.
His brain might just explode when he reads this.