(CBS) After playing a pivotal role in giving the Blackhawks a chance to win Game 4 of their first-round series against the Blues on Tuesday, Chicago forward Andrew Shaw had a forgettable final few minutes in the eventual loss.

With just more than two minutes remaining and the Blackhawks trailing 4-3, Shaw needlessly took an interference penalty, negating Chicago’s ability to have a man advantage in pulling the goalie.

Then after the Blues appeared to score an empty-netter with 34.8 seconds left, the NBC Sports broadcast appeared to show Shaw shouting a homophobic slur from the penalty box. The NHL is investigating Shaw’s comments, a league official told the Chicago Tribune.

Shaw didn’t recall exactly what he said in the moment, saying in a postgame interview, “Emotions are high, I don’t know what I said.”

The empty-netter was waived off after a review because of offsides, but the Blues held on for a 4-3 win and 3-1 series lead. Shaw then got in a tussle after the final whistle.

Shaw had a goal and two assists in the loss.