Hi Malek, got your pm, but I'll just reply here for the benefit of others.
First, let me explain the types of camera output, which there are three altogether:
1. RAW: RAW output is unprocessed data straight from the CCD. That is to say it is the "raw" data from the CCD. These files are unusable until they are processed. Think of it as the digital equivalent of film negatives.
2. JPEGs: These are picture files that have been processed in-camera based on your WB, saturation, contrast and sharpness settings. These files and usable straight from the camera and in Oly's case, comes in three compression rates: 1/8 (highest compression, lowest quality), 1/4 (standard) and 1/2.7 (lowest compression, highest quality).
3. TIFF: These are in-camera processed (same as jpegs, based on your camera settings) UNCOMPRESSED files.
So both you and your friend may be correct. The camera may have been set on more aggressive saturation and contrast. Or, the picture has been PhotoShopped and the saturation and contrast have been increased from there. Or both done.
From my experience with the E-300 what works for me is to set saturation, contrast and sharpness all on +1. This gives nice and punchy jpegs straight out of the camera, most of the time the only post-processing I do is to adjust the WB and exposure a little.