I was raiding a base with stooki today and we used my orb, when we shot it i did /drop and i then holstered my psg-1. After the holstering of my PSG my Orb got removed from my inv and it did not get dropped.
steamcommunity.com/id/finniebox/screenshots/
Just look at all the chat screenshots. Maybe stooki can give us some video proof, not sure tho.