something like this happend to me. I was in a battle and before it ended notifacations popped up and said I finished 2 goals before I was at that part. It took the fun out of that dungeon since I was playing with 3 others on different skill levels and levels (some of them were re doing it for fun). This happend all throughout the dungeon but it never happend again.
Little Nessa Lanyard Level 47
That did happen to me once though (treasure chests popping up before they should)