what? Of course you do. If you want to prove someone had something you need to prove that something even exists.Nobody knows, it was black ops.
You don't need to account for every ounce of the substance.
http://www.centrostudisport.it/PDF/TAS_CAS_ULTIMO/64.pdf
Read 195 - 202 and come back to me.
The idea that you can allege players got a substance, but you can't prove they ever had the substance because you can't even prove how much there was is laughable. Sorry.