Fake? I can usually spot the fakes a mile away, but this one is confusing me. It seems plausible, although I've never had my airbag go off from a slight tap. Also, the camerawork is a little too steady and too focused on the events at hand. I would expect a much bigger reaction from the person with the camera and the skateboarders.
I'm pretty sure its fake. If it is, it's a really good attempt at creating a viral video. I wonder who's behind it.