Just FYI, not sure if this is rumor or truth, but I was talking to some friends about this story yesterday and one of them said that the person had snuck back in to find his hat that he had dropped when he had been on the ride earlier.
I guess he doesn't need the hat now. Okay, that was bad. Even for me.

But it does make me think of a local story here in Phoenix.
There is a small amusement park near my home that has a large roller coaster. Next to the amusement park is a canal. One year, the canal was drained and they found all sorts of things that officials presumed belonged to riders of the roller coasters. Among the items mentioned were dentures (!), toupees and wigs, hats, sunglasses, money, you name it. If it isn't tied down, it's probably going to disappear when you ride a roller coaster.