I'm pretty sure the oem is not hooking up every rma drive and looking for files.
"well, new rma drive? Let's pop it in the USB caddy and see what's there... Hmm, some files... jpgs... Mpegs... Oh look. Pdfs with embedded viruses. Good thing we didn't connect this drive to... Oops"
They're sending that thing straight to the industrial degausser and then certification for possible resale.