I wouldn't say that a worker did it, but at this point anything is a possibility.
I've never been there before, but have plenty of friends and family who have. It's a place of imagination and pretending to be someone you're not.
JMO, but with it having gone on that Sunday, the 17th, and it having been yucky weather, I would think that everyone who attended would be extremely worn out and sleeping heavily, therefore would not easily notice if a fellow camper left early morning or if someone came and dumped something there in the trash early morning.
I'm sure that normal functioning and less-than-normal-functioning people both attend the faire and or work there.
Sometimes it's hard to tell a goose from a duck when you're in character (which, from my understanding, both workers and attendees generally dress up and "play the part"). JMO, but it seems like a place and people to check out...
Or it may be that I watched American Horror Story and realized that anything is possible, especially when you're an out-of-the-box thinker.