The Canucks were 2-for-6 on the power play.
"There's been games where I've said they've been good and just haven't scored. I didn't think they were very good tonight," Green said of the man-advantage. "I didn't think they were sharp, passing wasn't sharp, on the outside."
Milan Lucic one-timed a pass from Andersson in the slot with 25 seconds left in the first period to make it 2-1.
Andersson was removed from the power play and the Flames' top defense pair, according to Ward.
"We all played well after the 2-0 goal," Andersson said. "To get one with 20 seconds left in the period, it's obviously a momentum shift."
Elias Lindholm tied it 2-2 at 10:40 of the second after Horvat's turnover to Andersson at the Flames blue line created a 3-on-1 rush.
"We're happy we had the push back and obviously got into the overtime," Horvat said. "In my opinion, we shouldn't have gone to overtime in the first place. We made, including myself, just a bad giveaway and it's unfortunate, but we've just got to learn from it and move on."