Where is a patriotic leaker when you need one?
Thousands of copies of the whole 300 page report as a PDF or MS Word file would easily fit on one micro SD card. (The days of secretly copying 300 physical pages of a document on a Xerox machine, and the trying to smuggle them out of a facility are long gone.)
There are probably even smaller storage devices, but Micro SD cards are everywhere. Any document file could be renamed as something like an mp3, encrypted and stored on a Micro SD data storage card in a smart phone, camera, DAP, etc. (If a 77 y/o retired guy like me who is half as tech savvy as his younger counterparts can imagine this scenario, millions of others can also come up with the same ideas.)
Text files, on average, consist of a whopping 677,963 pages per gigabyte.
Microsoft Word files typically average 64,782 pages per gigabyte