If it's not already. I don't know.

But at the end of the season one game should be randomly selected to be intensively examined on how well the reffing was. Were they missing calls, calling unfairly in some manner. Or overly ticky tack?

I don't want to say that they should be fired, or face any real criticism on that one game. But if it does happen that some "errors" occured, it opens up a bigger analysis on the refs performance in other games that season.