"I'm not going to stand here and say the calls were right, wrong or indifferent," he said. "If you start complaining about that, that's an excuse. We showed a lot to come back."
It took the Leafs until 14:38 of the first period to get their first shot on goal, but they held Montreal to a 2-1 first-period lead.
Galchenyuk put a spin-around shot from the slot past Bernier 12:38 in, and Pacioretty scored on a backhander at 14:02.
After Joffrey Lupul hit a post, Kessel slipped a pass that van Riemsdyk deflected at the net, only to see it go in off Budaj at 17:34.
The third period saw van Riemsdyk get his second goal of the game on a short-handed breakaway at 5:28. Five of van Riemsdyk's 26 goals this season have come against Montreal.
Tyler Bozak sneaked a pass through traffic that sent Kessel in on a breakaway to beat Budaj at 7:43.
"Bozak made a spin-around, behind-the-back pass and it went through two skates, a couple of sticks and ends up right on Kessel's stick for a breakaway," Pacioretty said. "I was right there with Kessel, but I didn't see the puck coming until the last second."
Montreal coach Michel Therrien called a time out to settle his players and it seemed to work as Subban tied the game to force overtime.
"We got on our heels after (Toronto's) third goal, and we just needed to calm down," Therrien said. "I felt the bench was really down and I just wanted to say there was still a lot of hockey to be played."
The Canadiens and Leafs have split their four meetings this season, with their last regular-season game set for March 22 in Toronto.
NOTES: Montreal's Ryan White missed his second game with the flu, while Carey Price (lower body), Brandon Prust (upper body) and Michael Bournival (concussion) were also sidelined. Francis Bouillon was scratched. ... The Maple Leafs called up Peter Holland from the AHL and he centered the third line, bumping Nikolai Kulemin to the wing. Dave Bolland remains out with an ankle injury. Colton Orr, Trevor Smith and Paul Ranger didn't dress.