She didn’t mention that, she mentioned the subpoena.
Unless I misunderstand your meaning of "that", she said:
No, the documents he’d stuffed in Mar-a-Lago’s ballroom, bathroom and shower (among other highly secure locations) included information about our nuclear weapons programs, the defense capabilities of the U.S. and other countries, potential vulnerabilities of the United States and its allies to military attack, and plans for possible retaliation.She did not said, "The subpoena claims that he...", she said he did it; and she is in no position either to know that he did it, or to know what was actually in the boxes as claimed.
That was my point in linking the other article, which is really worth considering in detail.