Just a thought on the OP article: it identifies the dancer as a martial artist, which seems irrelevant to the story. Many traditional martial artists practice a set of choreographed moves called forms (or kata or hyungs) that They practice daily. They appear dance like, especially Capoeria (sp?) which is very acrobatic and dance like. Some styles even specifically call this dancing. I think it likely the guy was practicing his forms, rather than spontaneously getting his groove on.
Take a look at the policemen's footage when they approach him, before they interrupt his practice, dance whatever. To me it doesn't quite look like dancing, but it also doesn't look like martial arts. I think people from the area describe it as dancing in the OP video.