OK, let's game this out......
1. Person X, a Depository employee, comes forward to the authorities with curtain rods s/he has found in the Depository
2. Person X is thanked and told, 'Don't worry, we will look into this'
3. Curtain rods are submitted to Lt. Day's lab (3/15/64)
4. Curtain rods are tested for Mr Oswald's prints
5. Curtain rods are formally released (3/24/64)
6. Person X is shown the submission/release form and told, 'OK, so we looked into this and Oswald's prints aren't on them----we ask you not to talk to anyone about the rods, it would only cause confusion'
7. The submission/release form is kept on file for the contingency that Person X----------or someone Person X has told-----------goes public: the form allows the 'investigating' authorities to assure folks that this was "looked into" thoroughly
8. Word of the discovery of curtain rods at the Depository spreads, however, and Mr Roy Truly is asked to give an on-the-record statement that no curtain rods were found at the Depository