1. I have 2 of my slots used up, and am not carrying xbow or bolts.
2. I see a dead xbowman with arbalest and bolts on the body.
3. I pick up the xbow and find it has no bolt loaded.
4. I now pick up the bolts and the xbow is dropped.
5. I pick up the xbow again and it is now loaded. the bolts seem to have vanished.
I have repeated this many times and it seems to consistently happen. It only takes a second to perform and you get a free loaded arbalest.