Per the report, this is leaving out many other reasons. Here is a link to the Hur report. There is an Executive Summary that starts on PDF pg 5 (report pg 1). The reasons for not charging start on PDF pg 8 (report pg 4). Here are the reasons listed, in order, re: the most plausible charge - the Afghanistan documents [my comments in brackets]:
For example, Mr. Biden could have found the classified Afghanistan documents at his Virginia home in 2017 and then forgotten about them soon after… For a person who had viewed classified documents nearly every day 4 for eight years as vice president, including regularly in his home, finding classified documents at home less than a month after leaving office could have been an unremarkable and forgettable event. [Any normal person forgetfulness - not poor memory]
Mr. Biden’s memory was significantly limited, both during his recorded interviews with the ghostwriter in 2017, and in his interview with our office in 2023. And his cooperation with our investigation, including by reporting to the government that the Afghanistan documents were in his Delaware garage, will likely convince some jurors that he made an innocent mistake, rather than acting willfully-that is, with intent to break the law-as the statute requires. [Part of your mentioned reason that you’re conflating with another - but it’s about remembering if they were even there or not, at least 7 years prior - see next reason]
Another viable defense is that Mr. Biden might not have retained the classified Afghanistan documents in his Virginia home at all. [This reason to not charge has nothing to do with memory]
When Mr. Biden told his ghostwriter he “just found all the classified stuff downstairs,” he could have been referring to something other than the Afghanistan documents. [This reason to not charge has nothing to do with memory - Biden was almost certainly not referring to this if you read the full quote, but rather a letter to Obama]
We have also considered that, at trial, Mr. Biden would likely present himself to a jury, as he did during our interview of him, as a sympathetic, well-meaning, elderly man with a poor memory. Based on our direct interactions with and observations of him, he is someone for whom many jurors will want to identify reasonable doubt. [Your reason]
Biden’s Personal Notebook
The other classified things, would be Biden’s personal notebook - his diary. It contained mostly personal things that would not be classified much less considered a presidential record that NARA would even keep (Hur compared to Reagan who did the same thing for precedent). It did include some classified information. In addition to all the reasons above, it would be a hurdle to determine whether this was not something he could keep at home.
The “disclosure” crime, telling the ghostwriter “classified” stuff, all came from Biden’s notebook - not the marked classified Afghanistan documents which may or may not have been in his home. As with all the other problems listed above, it’s not even known what was shared - the personal stuff or the “classified” stuff (I put it in quotes as I’m pretty sure nothing was mark classified in, ya know, his diary). This is grasping at straws and it would not be expected for Biden, most people, to remember what he told a ghostwriter 7 years ago.