How to Open a Beer Bottle with a Piece of Paper

There's some discussion on the YouTube.com page over whether there is a coin in the paper (which you can supposedly see at 1:31) or not. To me it looks like his finger or a slight shadow, and I really don't know how you could pop open the bottle with the curve of a coin. Interesting either way.

EDIT: I tried this a couple nights ago. Now I have a gash across three of my fingers on my right hand. Either it doesn't work, I'm just dumb, or it's some unfortunate combination of those two.