'Can' be replicated by using ladders with a two weapon, one on the back and one in both hands. (when the bug is happening, the two handed weapon will be held only in the right hand and the players arms/hands will be held in the position as if no weapons or items are held in the hands.
Detailed:
- Equip 2 two-handed weapons - One on your back and one in your hands.
- Use any ladder (deer stand and such).
- Main hand weapon can sometimes disappear (be unusable but still visible in your RIGHT hand.
- If it didn't do the above the first time, repeat until the bug happens.