There appear to be a couple of problems with this quest:
1. I believe the dynamic layers are screwing up the selection of shoppers (Irate, Happy, Indecisive). You shouldn't have to wait around 40 minutes waiting for an indecisive shopper to spawn...especially when five other players are waiting around for the same thing.
2. This issue is compounded further by the amazingly short sighted decision of including a form of this quest in the dailies.