The NBA does something really neat. For close games they publish an analysis of the last two minutes of officiating. Apparently this is done for parts of every game and given to the officiating teams for evaluation and improvement.
I think something along these lines for the NHL would go a long way with increasing transparency.
https://official.nba.com/2017-18-nba...inute-reports/
For as much as people complain about reffing they get a lot right, their mistakes are glaring though