On item retrieval missions, you will often get a dialogue popup box that confirms you’ve retrieved whatever it is you went to get. This sort of implies the mission is complete – but it’s not. You still need to hunt down and kill all the remaining enemies in the associated encounter.
This should either be changed to an item description that properly describes the state of things (or, even better for a mercenary company) or should let the player be clever and actually retreat from the associated battle with their prize rather than stay and fight to no purpose.