You are wrong my friend the s5 pro is 12 mp. quoted directy "it features 6.17 million 'S photodiodes' (normal DR) and 6.17 million 'R photodiodes' (highlight DR) for a total photodiode count of 12.34 million."
They're legally allowed to say that it's a 12 MP camera, and guidelines specify that it may even be better. This is the same reason Sigma is allowed to call the SD14 a 14 MP camera when it's more like a 5 MP camera (although it really does produce some amazing results in some respects that make it better than other DSLRs with more pixels). However, in spirit, it's deceiving because on the Fuji, it takes 2 sensors to contribute to one pixel on the screen. The 12 MP photos are interpolated, so half the pixel info is interpolated. When you factor in the colour interpolation done in the images produced by all DSLRs (with the exception of the Sigma SD14), the camera is doing quite a lot of "guessing".
However, the interpolated results from the Fuji are quite good compared to other cameras.