In my age group, the referees (usually R8s and R9s) tend to be very inexperienced. Many calls are incorrect (don’t worry, I was an R8 ref a few years ago, so I know they were wrong). Is it frowned upon for a referee to change a call once made after players and/or coaches argue? I am an arguer (i.e. refs I don’t personally know generally don’t like me), and a ref has never changed a call, whether they know it was wrong or not. Can they, or is a call final no matter what?

Answer (July 7, 2012):
Yes, a referee may change a call, provided that he or she has not already restarted play. And, even if play has already restarted, if the referee realizes he has made a mistake, as long as this realization came to him or her before the restart occurred — and only the referee knows if that is true.