hey yeah, that EXACT thing happened to me just the other week...
I had already discharged some of my best one-liners and was showing real progress with a couple of promising young things who hadn't been in long enough to be bitter, twisted and all that... anyway, one of the boilers who somehow snuck in decided enough was enough.. she'd already eaten her muesli bars and drank the free p!ss and she decided to go back to her room to phone her cat and she dragged off the youngsters with her.
I had to go back down to the bar and start all over again on some stragglers. Yes... outrageous, but I assure you it is true.
No jumpseat for THAT old duck ever again...