Well, I can't say I entirely disagree with the cops call to pull him over. It is a heavy piece of metal, and if the brakes aren't set up properly, then it could be tough to stop. It still would be considered a car (even if it has no motor in it) and as such, it is not licensed and not insured (the main reason that it is a big deal is that it is a car still). Finally, at 15 km/h, it would really be holding up traffic (even more so than a typical bike taking up a full lane).
Still, there is a part of me that thinks that it sucks, since it is like a velomobile of sorts... the moral of the story is... don't build your velomobiles out of cars.