When you leave the keep at the top, do you have to completely finish your turn, or once you leave do you just stop immediately? The reason I ask is that I got out the keep and had a stumble in my final hand. Did I need to add my cube? Obviously I don't want to be adding my cubes to the clank bag as I don't want to dilute my opponents' damage cubes with my useless cubes.
Thanks Paul for the answer. @ OP: The same question came up during my last game too. It can make a difference if the player who escapes the dungeon still adds his clank! cubes into the bag. On a dragon attack the players left in the dungeon have a little less chance that their cubes get drawn.