Ooops. Sent this to Juan offlist, but meant to copy the list on it too.
However the idea that a professional seller of jewelry is going to make a big sale like that, without even COUNTING the bills because he had been chatted up with some nonsense about the subway system is...not plausible.
It's all about misdirection, and subtle cues. I haven't seen Derren's explanation of this particular example, but from what I know of the subject, here is my take: The chat about the subway is misdirection. He makes it a point to start moving his hands, point this way and that about "directions" .. that gets the cashier looking away from what they're doing and subtly distracted, looking at him, and away from what they are supposed to be doing. Then he mentions being uneasy about the subway. This is an important part. Because it will tend to make the listener remember a time they were uneasy or had a bad experience on the subway. This memory, and any associated emotional impact, puts them entirely "within their head" for just a moment. Then comes pay off. "Go ahead, just take it. It's fine." while handing him the paper.. overtly referring to his friend, telling him to take the subway, but covertly a command to accept the "money." The jewelry store guy DID realize it, shortly after, as well as did the guys with the wallets. That is to be expected. The suggestible state doesn't last indefinitely. If you look into his work, he has admitted that he has more failures than successes depending on the complexity of the trick, and that his show is about entertainment, primarily, and so only the successes are shown. It's conceivable he stages some things, too. Like any magician.
I do think that Darren is socially engineering people. The people who watch their videos, IF they think are real...
But if you believe a talented magician never manages to fool people successfully, you're naive. Yes, they'll stage stuff too, but that is hardly the point. The skills of illusion, and "mentalism" are quite real.. and if you watch more of his stuff, especially the longer videos or full episodes where he breaks down the hows and whys of it working, perhaps you'll be less likely to say its fake. It's easy to dismiss a magic trick as "camera edits" when you just have a 3 minute video. It's a bit harder when the magician explains the whole thing to you. In the videos I linked to, he uses a lot of body language mirroring. Whatever movements the subject makes, he mirrors with his own body language. Then, when he feels like he has the person, he'll move away as a test and do other movements to see if they have begun mirroring him, in return. Then he handed them the water bottle, while asking for something in return. They continue to mirror, they have received, so they'll give. This is doubly effective, since there is a subconscious desire for reciprocity. And then yes, they realize it. Their rational mind kicks back in, and they'll realize it. But the fact that the rational mind can be so easily subverted, should give one pause. He uses a lot of techniques, but "neuro-linguistic programming" (NLP) is the bread-and-butter. I have some familiarity with the techniques.. book learning, basically. I've never employed them, at least not consciously, but I can say that I see a lot of this stuff in advertisements and politicians speeches. Seems to me there is something to it, whether Derren is 100% above board, or not.