I'm not seeing how we can be that off for the PS3.
Just look at the Weekly Hardware chart. If you added up America, Europe and Japan, you'd have noticed a "Rest of the World" number where PS3 outsells X360 3:1 (or even more) every week this year. This ratio is completely fictious. Remove about 15-20k overtracking every week and you get a PS3 overtrack by at least 200k alone.