How is this possible?

I was just in a dungeon and wanted to skip Landslide like I have with 100’s of other groups and I was dungeon lead, so I pinged the map to move on and all but the tank followed me. We where almost done with combat and I got kicked from the dungeon, it has been my understanding you cannot be kicked during midd combat or immediately after, so i would like to know how i got kicked so quickly?