What Can We Say About the Versailles Time Slip?

Parapsychology offers several theories about the time slip at Versailles. One is that it was a hoax, but they didn't seem to have much of a motive for hoaxing. They were prestigious academics who would hold down those jobs for years. Could this be a case where they imagined all these things? It's not impossible; you don't imagine something like this and believe it was real when actually nothing happened.