Trump is saying one thing, the FBI is saying a different thing.
The documents were in Trumps possession prior to the raid, so they could not have been planted by LEOs, as some have speculated.
One defense that is being raised: The classification markings on the actual documents were never changed even though multiple people have confirmed that the declassification order was given for these particular documents.
The arguments and subsequent analysis now has to do with these actual documents and whether or not they were truly declassified or actually classified.
This could get a little confusing.