I would never call you a liar, Mike. Passive aggressive, maybe, but never a liar. :-D
My question would be how much? How many of these have you seen? Are you sure there was not cement bed under the tile/thin-set? Even a thin one that perhaps could be mistaken for the thin-set used to attach the tile? Perhaps there's something about Luan in this equation. I know most 1/4' Luan is quite a different animal than other sheet goods with how stiff Luan is compared to the stuff they put in the middle of the sandwich. Perhaps that stuff in the middle allows for flexibility like the Schluter Ditra sheets do.
Not arguing, here, just honestly curious.