Yeah, the "cut" looked suspicious at first, still does technically, however, watching it closely, it is one continuous shot, the frame just jumps in a bit. Basically in one frame it zooms in for some reason. Not sure if this happened because of the text you applied at that point, or if it was some weird glitch in Youtube, but in the end, you've got me fooled.
I mean, the effect, if described, is the same as the way many do Card on Ceiling, save for the fact that you have the spectator clearly shuffling the card into the deck, and placing the card in the box.
How you would manage to control it in those conditions, and get it through the box, is, quite frankly, beyond me. That's not something I can say often.
I would imagine what ever you are doing here could be used for far more than just a Card on Ceiling effect, yes?