I wasn't familiar with that type of braka, and had to look it up. I can't see a hub on the back wheel, and I don't see him using any type of back-pedal or braking action to stop (just his feet).

So, yes, for those few bikes that don't have conventional brakes, this lighting system may be an option.

That doesn't change the fact that this product will be useless to the majority of people who might purchase (sorry, sponsor :-) it through KickStarter, at least without sacrificing the ability to stop.

The fact that this isn't called out in the video or text is deceptive. There's no way he isn't aware of this serious shortcoming.