In a recent interview, Tim Peel admitted to favouring star players when making a call. In his view, fans wanted to see star players on the ice as much as possible, so if a call was on the borderline of being a penalty, he wouldn't make it.
Peel tried to cover himself by saying that blatant calls were still made, like a cross-check to the head. However, the issue is that most penalties in the NHL aren't obvious, and he was the one determining whether or not to properly enforce the rules on a level playing field.
Peel was fired from the NHL in 2021 for being caught on a hot mic saying that he was trying to give the Nashville Predators a penalty as a make-up call, essentially calling them for something that might not have been a penalty in order to make the penalties even between teams.