It's one thing to have such material in error and then return it upon discovery
In the case of TS/SCI material, even that would be evidence of a serious offence. Nobody has such material 'in error' without someone having broken the rules bigly.
We know Trumpo did not pack those boxes,move them to a truck, unloaded the truck at Mar-A-Lago, and move them to the closet where they resided for months. Now the question is who arranged this removal, at whose orders, and did they know what was in the boxes? Confederates, or dupes?
This is going to get oh so investigated, and somebody is gonna squeal. Knowing Trump, he had a sucker engineer the dirty work. Who?