All Japanese be killed in an earthquake

Korean said 「All Japanese be killed in an earthquake.」

http://www.youtube.com/watch?v=nYMqQmajp8g

Hey Japanese people.
So you guys are already contaminated with the radiation?
Isn't it just scary?
Well I'm guessing that devastating earthquake is going to
hit Tokyo and kill a lot of people,
which I really can't wait for it.
I'm always thinking Japanese people dying, but I can't kill them
directly, so it was really exciting to hear that Japanese people are
dying from the natural disaster.
Well, im going to stop here and watch Japanese suffer more from
the earthquake.
Hope you guys die soon.

The dude is speaking in Japanese in the video... how do you know for sure that he isn't a Japanese person who hates Korean, and to fuel that he took it upon himself to say such hateful comments. [Don't worry, I love Japanese people, but I don't like people who intentionally hang the bait out.]