I just completed depth 19, or rather was about to, when my gate crashed, I decided the best process was to quickly close and re-open the game, thus making it count as a D/C. the team decided to continue down to floor 20. When my game reloaded, I was back on depth 19, (Recorded now as level 20), no enemies, No team mates, Still able to see them typing and their loot collected, however I was unable to do anything to assist them, I was just stuck in the previous level wondering around.

Solution: making people who are D/C'd when a level changes go to haven.