Gibson was pulled against the Blackhawks after allowing four goals on 22 shots.
"It's going to happen to everybody throughout the year," Gibson said. "It's part of the game."
Kyle Brodziak scored two goals in the third period, and Jake Allen made 27 saves for the Blues (17-7-1), who are 2-2-0 on a five-game homestand.
The Blues were critical of their penalty kill after allowing two power-play goals for the second game in a row. They have allowed at least one power-play goal in 15 of 25 games and are 27th in the NHL on the penalty kill (75.9 percent).
"I'm not exactly sure," Brodziak said. "We're getting scored on quite a bit all year, basically. Early on, we were getting scored on, and that might have hurt the confidence. It felt like we were starting to get it back together, but the last few games, same thing. We give up two more tonight. It's really the story of the game pretty much.
"... A game like tonight, penalty kill could have found a way to win a game for us. Instead, we found a way to lose a game for us tonight."
The Ducks were 4-for-4 on the penalty kill despite allowing 13 shots.
"Your No. 1 penalty-killer 99 percent of the time is the goaltender," Carlyle said. "Our goaltenders have (given) us quality goaltending all year. Tonight was another example of that."
Vermette scored to give the Ducks a 1-0 lead at 4:17 of the first period when the puck caromed off his body after Allen got a piece of Roy's shot off a rebound.
The Ducks took a 3-0 lead with two power-play goals in the second period.
