The Blues thought they had taken a 2-1 lead with 7:54 remaining in the third period when Vladimir Tarasenko scored from the slot off a pass from Jori Lehtera, but the Blackhawks challenged that Lehtera was offside, and the call was reversed after a lengthy delay.
Blackhawks coach Joel Quenneville screamed from the bench to get the officials' attention.
"Someone on the bench yelled, 'It's offside!' and we got it late, I was screaming like a crazy man," Quenneville said. "They give you sometimes the benefit of the doubt. I don't know what the timeline is. This year, it's kind of new; I don't know if there's a real time limit, but I think they give you time to take a couple of looks at it.
"A player initially said it was offside. Then you have communication between the coach and video and says 'Check it out, let's look at it.' Had to get the referee's attention late. ... The offsides ones are the ones that are a little more clear. It's not the ones at the net with contact. There's a lot of leeway, a lot of interpretations, but the offsides are pretty straight, cut and dried."