That was my first thought too, but then of course the scout might have thought that he was 4* or 5* before he had him playing a training session, and after this training session the star rating has been updated. This would suggest that the star ratings alone are very unreliable.
However, I do not believe that this is the case, but it is a possibility.
that sounds interesting. i mean, it makes sense, doesn't it. so, star ratings without second scouting, not so reliable. with second scouting, you get the 'exact' star rating with an additional trend given by the grade rating (+-). an interesting point of view.