Judge Alison Nathan sided with neutral discipline arbitrator James Oldham, who cut Wideman's suspension for knocking linesman Don Henderson to the ice from 20 games to 10. The NHL had sought to have the 20-game ban restored.
The NHL said in a statement released Wednesday night that it disagreed with the court's decision, but understood the standard needed to overturn the decision. The league said it is ready to turn the page.
Wideman was suspended 20 games for hitting Henderson and knocking him down during a game against the Nashville Predators on Jan. 27, 2016.
Commissioner Gary Bettman upheld that suspension, but Oldham ruled that Wideman did not intend to injure Henderson and reduced the suspension to 10 games.
Oldham was fired from the position last summer.
In its statement, the NHL said it hoped the next time there's an appeal, the neutral discipline arbitrator will apply the standard of review it and the NHL Players' Association agreed to in collective bargaining. The league claimed that was not the case with Wideman.
Nathan wrote that the NHL did not show that Oldham exceeded his authority.
Wideman served 19 games of his suspension before it was reduced to 10. He was returned a portion of the salary he lost.
Earlier this season, Anaheim Ducks center Antoine Vermette was suspended 10 games for slashing a linesman. Bettman upheld that ban, and Vermette served it without appealing to the neutral discipline arbitrator.