I lived in Japan, and this would be very uncharacteristic of a Japanese person. (Yes, this seems like a gross generalization, but if you lived there you would understand what I mean) I wish they would investigate the source.
I dont see why it would be "uncharacteristic" for one Japanese person to do such a thing. A single stereotypical characteristic trait probably doesnt match like 30% of a population. All it took was one crazy fan of another skater with an obsessive and jealous mindset.