The NHL rules on Nathan MacKinnon's slash on the referee

In a 5-1 loss to the Boston Bruins, Colorado Avalanche standout Nathan MacKinnon appeared to slash a linesman.

-

And it appears that, following a review, the NHL has decided not to discipline MacKinnon:

-

Credit: HF

Also read on Hockey Patrol :
Two of the four final names for Utah's NHL team revealed by owner