You know when you really, really, really need a wee?
Now, it could be that they ran off to the loo, stuffing the sheet into the lowers in their panicked haste.
You might wanna re-wash your hands before reading the other scenario; they needed a wee so bad, they did it in the lowers; the were holding the QA sheet in their hand by their fly and the sheer ferocity of the piss stream drove the document clean out of their hand and embedded it in the lowers; not wanting to touch it, let alone cause undue attention by trying to dispose of the sodden mess, they just went about their business and filled the remaining volume with oil to disguise their actions.