Eh, having the exact number of chairs on stage with the exact number of volunteers doesn't make it fake.
There could have been something not filmed like "I'm going to need these many volunteers for this demo" waaaaay beforehand.
Stage hypnosis is tricky. By the end of the demo he only had one or 2 people actually listening and actually paying attention. Those people stayed under.
Stage hypnosis is a beast in of it's own.
1. First, the people most likely willing to step on stage are going to be people willing to act like an assclown.
2. He put the premise that hypnosis is not fake, and then challenged people, is also why some people on stage didn't really do anything, "I'll fool him"
3. The guy's not fake, but it's "Showy" and it's meant to be "Showy"
Hypnosis itself is real. You really can perform surgery on people in trance. (Esidaile State).
People are receptive to suggestion, and are suggestible.
But, yes you can't be made to do anything that you don't want to do… though manipulative assholes can shape and preface things to make it more enticing to want to do those things that you thought you might have not wanted to do.