It's one thing to be good at your job, but the only way such a thing would be even possible without being psychic would be to have some sort of "pre game" with the participant. If you've never seen a deck of cards before and they are in an order that neither you nor the participant know, it's impossible to know where any particular card is without psychic ability...there's no method to be had . So I guess we'll just chalk it up to there being more going on than meets the eye and leave it at that. I guess I'm using this to get my own thoughts out on paper so to speak.
So, what you're basically saying is that because you can't figure out a method, it must be stooges? Otherwise it would be impossible....but surely that's the whole point! If it didn't look impossible it wouldn't be magic!
Think of it this way: To a lay person, having the card they freely named be the only card face-down in a deck you never touched, is completely impossible. How could you have known card they would name without some 'pre game' with the participant? There is no way you could know in advance what card they would name, therefore the participant has to be a stooge. There can't be any other method to it.
But there is. We all know what the Invisible Deck is and how it works. But to the uninitiated the method is beyond the scope of their thought process/problem solving skills, so they just assume stooges are involved. To those of us in the know, the method seems obvious.
Just because you don't know Mr Turners method, doesn't mean there isn't one. I don't know how long you've been into magic but it come across as a bit egotistical to assume you know everything there is to know about mentalism/magic and therefore because you can't figure out a method then Mr Turner must be 'cheating' somehow. Because, obviously, no-one could possible come up with something that could fool you that badly.
Just accept there is always going to be someone out there who can fool you....and just enjoy it! The longer you're in the game the less you will have the joy of being fooled, so enjoy it when it happens and don't ruin it for yourself.
Peace
Rev