Play on laggy server
Do something, for example drink a lot of water.
When done, take rifle in hands.
Walk away.
After a while, you go into unvoluntary drinking animation while holding rifle in right hand.
After animation is complete, rifle is in right hand.
If you select aggressive stance (SPACE), the rifle is still in right hand.
Press attack (LEFT MOUSE BTN) and the rifle shoots diagonally up into the air. Hands do not punch.
Now you can't do anything - hands are occupied and can not be emptied. The only recourse is to log out and in again.