Steps to reproduce:
- Be close to weight limit
- kill mob with something heavy (like 2h weapon)
- loot mob, but keep heavy thing stuck to cursor
- Note that you are encumbered
- give 2h still in your hand to pet
- Note that you are still encumbered
This seems to wear off when you next loot anything, and I don't know if it's just a client/visual issue, or you are REALLY encumbered and suffering the run slowdown and lower AGI or not.