All you that thinks Collina is a good referee, you are right !!!
Most Italian referees are very good and many people in the world thinks Italian referees are the best, as long as they are outside Italy, in European games.
The problem is when those great referees has to be referee in Italy in the league, because they are in a system where they are only doing their job. I think that what De Santis did in Juve-Parma was only his job, to let Juve win.