Question on the RAW files from the DPR review of the A77

This probably got covered when the A77 review came out but I was looking at the D4 studio image and comparing it to the Nikon D300s (as a proxy for my A700) and the A77. I went to download some of the RAW samples and noticed that the A77 file was smaller than the Nikon files from the 12mp cameras and more strangely, smaller than the A77's JPEG file. I've always been very unimpressed with the RAW shot at that iso in their test -- is there something wrong with the file or is it legitimately that much smaller than one would expect?