Being 'slain by the spirit' is something very real... some people have problems with evangelists becoming a successful leader, and financial success. I don't. I don't support them financially either.
But, seeing what happens in that video may make a average new-age spiritualist freak out, but it's far from fake, and is even semi-common in protestant non-denominational churches...
It happened to me years ago, and was the single event that turned my life around... something that cannot be explained. I have been at an event with hypnotists.. some people can be hypnotized, while others can't. I fall in the latter category.
When being slain in the spirit, something very odd happens, and it is a very physical reaction.. but at no time are you in pain... a great peace comes over you like you may not be able to imagine... perhaps something that may be able to be replicated in a sensory deprivation chamber, I don't know... but something physically happens the moment somebody who is a servant of God, and blessed with that gift in the spirit... it's just odd.
Is what's in the video real or fake? I don't know, but it does happen, and it can be very real. It's something that everybody ought to experience