also possible: notice how thick the floors of those rotating platforms are. skilled contortionists could hide themselves beneath a trap door or a false floor in the time that those curtains were down, and then they would use body doubles for the participants on the other side. all this would require would be eight skilled contortionists, four of which mingle and meander through the crowd as the trick gets set up. the four amongst the crowd would then get """chosen randomly""" and would fumble and stumble with the instructions to look like it wasn't staged.

More than likely.