I thought that leaving the trash in the stands for 12 hours was horrible until I read on and saw this gem-
In stadium kitchens, including the Diamond Club Kitchen and Bar, dirty dishes and pots were stacked on tabletops and in sinks. Counters were greasy and unwiped. Wilted lettuce and food products were left out on countertops.
I can tell you for certain at the RoseBowl and home Depot Centre they actually start cleaning BEFORE the crowd is gone.