I read a lot about how he might have pulled this off. From what I gather, the answer is basically a TON of preparation, plus multiple possible “abort points” to various tricks, and make sure to perform several tricks during a visit like this, and keep the cameras rolling the entire time.
I’m not a magic guy but that was easy to
Figure out. Show the cards one way. Let him see again turned around. Each card different top and bottom. When he cuts the orange watch his left hand go beneath. He prob has cards all over his body dep on which one Harrison picked. No research needed.