What's notable is that the claim Nagell told to the Army in 1969 (as can be seen on page 2 of the 4 page document here:
https://www.onthetrailofdelusion.com/post/is-this-document-the-smoking-gun-on-the-richard-case-nagell-story ) is that this claim is quiet simple. It does not have all the bells and whistles it does when it shows up in Russells book (ie a photo of Oswald and Nagell together being stashed away in a Switzerland bank vault, tape recordings of Oswald, and Nagells order to kill Oswald).
Is it possible that the simple version Nagell gives to the army in 1969 is the truth and then Nagell inflated this simple story when he told it to Russell in order to, as is stated at the end of that 4 page document, to embarrass the CIA?