True, but remember that the Fuji sensor is not a conventional one -- it is tilted 45 deg relative to usual sensors. I checked back, and this is what an earlier British Journal of Photography review noted about the Fuji S5 resolution:
"Doing the tests revealed maximum resolutions of approximately 56 lp/mm, 36-40 lp/mm and 28 lp/mm. These figures are consistent with the predicted ranges (at the Nyquist end of the scale) and support the notion that the S5's highest resolution corresponds with a genuine 12 million pixels rather than interpolation of a smaller number of pixels."
The lines per mm figures refer to the 12MP, 6Mp and 3 or 4 MP settings in the S5.
This is the first time KRW has tested a Fuji DSLR and I suspect he did not do a careful test and simply brushed off the 12MP setting as a "fake" increase in resolution.