And why Williams was disappointed in himself.
"I'm disappointed in general. Absolutely," he said. "I've got to know better."
Maybe Williams taking ownership of that moment will at least set an example for the rest of the Hurricanes, who all need to look in the mirror after their disappointing performance Sunday.
"He's a stand-up guy," Carolina center Sebastian Aho said. "Everyone can be better, and he says that out loud because when he steps up, we follow him."
The Hurricanes are playing a talented and well-coached Bruins team, who have won five consecutive playoff games since trailing the Columbus Blue Jackets 2-1 in the second round, but Carolina knows it hasn't come close to playing its best thus far in the series.
Before Williams' redirection goal with 8:43 remaining in the third period cut it to 6-1, Boston had scored 10 consecutive goals since trailing 2-1 after two periods in a 5-2 win in Game 1 on Thursday.
Mrazek struggled Sunday in allowing six goals on 25 shots, including a soft one to Grzelcyk from the left circle that opened the scoring with 4:38 left in the first period. While Carolina didn't give Mrazek a lot of help, Hurricanes coach Rod Brind'Amour has to at least consider switching to backup Curtis McElhinney for Game 3.
But Brind'Amour wasn't ready to discuss that after the game Sunday. He knows there are a lot of other areas of the game they need to clean up.
They have yet to find a solution to the Bruins' power play, which is 4-for-7 in the series, including 2-for-2 in Game 2. And after scoring on their first power play of the series and showing some promise on their other two man-advantage opportunities in Game 1, the Hurricanes went back to struggling in Game 2, going 0-for-4.
They are 5-for-45 (11.1 percent) on the power play in the playoffs.
"Looking back at the game, we were not good enough," Hurricanes center Jordan Staal said. "Our 5-on-5 play is not good enough, our special teams (are) not good enough. It's just all around everything. Everyone has to chip in, everyone has to grind more, and everyone has to be more desperate."