He is going by the NPD numbers that were released for November. There no way he could say the Kinect outsold the Move 5 to 1 unless he had the figures in front of him. He's not making a guess. He stating a fact from the data he released.
Considering the XBox 360 outsold the PS3 450K to 210K in the U.S. , I'm sure his number are pretty accurate in this case. He's only talking about the U.S. This doesn't include Europe or Japan.