Talk like that is what, we in the Ozarks, refer to as "pullin' yer leg." I really don't think they revealed any hidden secrets. (It wasn't the notorious dippin-dots guy was it?) Engineers who design major major amusement park rides know what they are doing. In fact, they can be sued for large amounts of money if they mess up. I'm sure they have drilled core samples all over that hillside to be sure of the geology beneath their feet. No known passages of the cave are beneath that area. If there were EVER any passages there, they have collapsed and eroded away millions of years ago, leaving a steep hillside. I don't believe there is any chance of a cave tour being interrupted by a roller coaster train crashing down on them.