I’m fairly certain Garland, with extensive trial court experience drilled down fairly deeply on the scienter arguments of whether DOJ could demonstrate that Trump had both knowledge of the nature of removing the relevant documents and the intent to maintain possession in violation of the Presidential records act. Each incoming President is personally briefed on those rules literally from the moment they walk into the oval office. (You generally cannot establish lack of scienter in a federal criminal proceeding by arguing there were ways you might have arguably achieved the same outcome legally albeit in practice you pursued another strategy).
I have to believe, however, that in this case, there was MORE than some minor violation of the rules requiring Presidents to turn over the chotchkas they receive from foreign government valued over $50 along with any communications from foreign leaders (which seems to be what the Trump lawyers claim are the contents of the withheld boxes). Just a hunch that they wouldn’t jeopardize the January 6/election overturn investigation with some nickle and dime Records Act violation and the predictable firestorm it elicited.