I've had a few occurrences lately of using the grouping tool to find a group (max CP healer) and I get a notification for a group, hit the big 'ole tick and then boom I get a notification that the group has been disbanded (instantly mind you) and I'm not in the group anymore. Not a big deal except the ever-not-so-helpful grouping tool seems to think that I should now have to wait 15 minutes for something I had ZERO control over. Not cool. Not cool at all.
I really think the coding for this condition should be looked at. Sure make the leader wait but not everyone who was just drawn into the group. If I manually quit the group sure absolutely make me wait 15 minutes.