At the beginning of the ambush, I casted Damage Shunt and used the Rune of the Rift to have a few turns without Ukruk interfering. Then I casted my favourite Spell (which is also the one causing the bug): Paradox Clone. After a few turns all the orcs except Ukruk were gone and I was sure I would emerge triumphant from the ambush for my very first time ... when my future self disappeared (I think it was killed by Ukruk but am not 100% sure), Uruk left and the exit appeared.
Basically I think the engine didn't differentiate between me and my future self, thinking I was defeated when the clone was killed (the stdout implied that the game tried to take the staff away from my clone

The point where it became a real paradox was that I didn't die when I got called into the past, thus Ukruk did not take the staff from me when I WAS the future self, implying that "in character" there are now two staffs in this timeline

God I love this class, even the bugs are more fun, it was almost worth not getting the achievement

Edit: Since I 'failed' the ambush, the people of Last Hope didn't take the staff from me, meaning I still have it
