Smith made a blocker save on Alexander Steen's snap shot from the high slot 1:15 after Hamilton's goal.
Frolik put Calgary up 1-0 at 7:58 of the first period. Hutton made a blocker save on Frolik's shot, but Joel Edmundson swiped the rebound off Hutton's shoulder. Play continued for 40 seconds before video review confirmed the puck crossed the goal line before Blues forward Tage Thompson was able to bat the puck out of the net.
"I've had a few where they have to challenge it, but never like that when you keep playing and then all of a sudden the buzzer goes on," Frolik said. "I was just like, 'Something's wrong, I guess.' Guys at the bench were yelling at me that it was in."
Schenn tied it 1-1 with a power-play goal at 1:26 of the second period when he stickhandled around Troy Brouwer at Calgary's blue line and shot off the inside of the post. Schenn leads St. Louis with 17 goals.
"Just Brouwer, a forward standing flat-footed and you try him one-on-one," Schenn said. "I was able to beat him and get a quick shot off and that's kind of all it was."