RAW shots are simply all the data captured by the Camera's sensor dumped onto the memory card with no processing done by the camera.
Were you shooting in RAW only or RAW+JPEG? If it's the latter, you will probably find that you have a B&W JPEG and a colour RAW.
On another note, you will get punchier B&W shots if you convert them from colour using Photoshop channel mixer rather than your camera.