Items will dupe in a chest if quitted after death using Task Manager

This Was Meant To Happen:
Going back to a previous auto-save

This Instead Happened
Actions that I had done before the Task Manager quit happened

How To Reproduce:
1. Make the game auto save a chest, with your desired items in your inventory. 
2. Before the game saves again, put the items you want to dupe in the chest
3. Again, before the game saves, die and quit using Task Manager

The image below contains duped Diamonds (there were 5 in the cave) the whole chest loot shouldn't be there.