I'll bet the show's writers had a Wal-Mart employee feeding them stories from the shop floor. I always assume that when I see shows getting things really true to life. Years ago, a mini series over here was set in a University and was uncannily true to life right down to things that happened strictly behind closed doors. I happen to know that a friend and colleague and long time employee at our university was feeding the storylines to the writer. We were both union reps so got to see the side of the place that they try to keep hidden.