simon was in on the trick. He knew it was the 7 of hearts and acted stunned.
Notice that the trick was presented in a way that made it seem like Simon's involvement added a degree of uncertainty to the selection of the card. But what it did was make the selection by the other three panel members completely irrelevant.
No - using a confidant or confederate is only for large stage illusions.
Generally, not only is that largely not needed at all if you can manipulate cards and do a bit of slight of hand, but it’s
generally looked down upon with close up effects - especially with card and coin manipulation.
I don’t think so. If you notice, it is only the last card which has the seven of hearts on it. He has another deck, with one of each card drawn on the back. When he hears “seven of hearts”, he reaches into his back pocket with his left hand, and grabs that card. When he grabs the deck, he uses sleight of hand to place that card onto the bottom of the deck that everyone sees. Voila. No need for anybody to be in on the trick.