With the puck seemingly still loose, the Flames and Oilers each had goals disallowed because the whistle appeared to be blown just before the puck crossed the line.
Edmonton's Zach Hyman's goal that would have tied it at 2-2 in the first period was called back when refs determined the whistle had blown. The puck was not fully covered by Flames goalie Jacob Markstrom as Hyman batted it home.
“The way it was explained to me was the referee lost sight of the puck," Oilers coach Jay Woodcroft said.
Then, in the third period, Tyler Toffoli's would-be tying goal also was called back when the whistle appeared to go off just before he banged in a puck in the crease.
Just like in the first period with Markstrom, Oilers goalie Mike Smith did not appear to have frozen the puck before the whistle went with Edmonton in front 4-3.
“You look at it, it’s a goal, but I did hear the whistle prior," Flames coach Darryl Sutter said.
A third goal also was called back for a different reason.
In the second period, Connor McDavid deked around Flames defenceman Noah Hanifin and drove the net, bumping Markstrom before Leon Draisaitl pounced on the loose puck for goal.
The goal was then disallowed for goaltender interference.
The Oilers went on to win 5-3, however, and tied the best-of-seven series at 1-1.