You should pretty much never trust magicians who "explain" how their illusions work. Sometimes they genuinely do explain it, but often, it's still another trick. Derren Brown does this a lot.
My absolute favorite "magician" was a card manipulator who demonstrated how several of the standard card tricks worked. Even showing the trick from the side and also from behind (his back to the audience so you see how he's doing it) the technical skill was amazing. It motivated me to learn prestidigitation. It turns out that my fingers are too short to do card tricks with standard playing cards (also too short for the fretboard of a classical guitar - I have to stick to acoustics & electrics).
For small fingers, bridge sized card decks are an option!
I used to love watching the Derren Brown specials until he did the one predicting the lottery numbers. That made me realize all of his tv shows could be camera tricks and paid actors.
Same here. It was the lottery episode that made me realise that he is willing to lie when explaining his illusions. I didn't feel delighted by the illusion, I felt lied to.