The Flames went 0-for-6 on the power play.
"Our power play had a chance to put the game away and wasn't able to do that for us," Huska said. "When you're up 3-1, it's hard when you let one slip away like that."
The Flames took a 1-0 lead at 14:18 of the second period.
Anaheim tried to rim the puck out of its zone but it was poked away, leading to a wrist shot from just inside the blue line by Weegar that was tipped into the net by Backlund.
Oliver Kylington made a long pass from the left point to Trevor Zegras in the right circle, who stopped the puck before shooting over the right shoulder of Wolf to tie it 1-1 at 11:49 of the third.
Yegor Sharangovich scored his own rebound to give the Flames a 2-1 lead at 13:55, and Matt Coronato scored on a drive to the net to make it 3-1 at 15:18.
"We should be disappointed," Huska said. "It's 3-1 and the game should be over, but right now there is nothing we can do about it. All we can do is make sure we're ready to go for the next game at home against Minnesota (on Friday)."
Husso was making his second start for Anaheim since he was acquired in a trade with the Detroit Red Wings on Feb. 24. He had not appeared since playing the third period of a 7-2 loss to the Blues on March 16.
"He was amazing," Gauthier said of Husso. "Stood on his head for us, easily could have been a different game, different outcome, but he was special tonight and we're happy he's on our side."
NOTES: Calgary forward Morgan Frost went to the locker room under his own power after being checked headfirst into the boards at 2:01 of the third period. Huska did not have an update. ... Wolf came in 3-0-0 against the Ducks this season and had stopped 82 of 86 shots (95.3 percent). ... Zegras has seven points (three goals, four assists) in the past seven games. ... Carlsson had two assists to give him 10 points (four goals, six assists) in his past eight games. ... The Ducks are 12-for 12 on the penalty kill in the past two games.