Montreal Canadiens defenseman Kaiden Guhle picked up a double-minor for high sticking after a hit from Tampa’s Brandon Hagel pushed Guhle’s stick into Brayden Point’s face, injuring him.
Both calls – the interference on Hagel and the high-stick from Guhle on Point – were made by the officials on the ice. You can see referee Francois St. Laurent’s arm shoot up after the contact. The quartet of zebras came together to discuss the play, at which time the linespersons could also report what they saw on the play, including the high stick that resulted in an injury.
Once the double-minor was called, St. Laurent and ref Jake Brenk headed over to take a second look at the play. Their options were only to confirm the call on the ice or to wipe out the penalty completely. If, for example, Point was injured by Hagel’s stick, the stick foul would be wiped out. As it stands, it was, in fact, Guhle’s tick that caused the injury. That’s all the review needed to confirm.
 
The high-sticking rule doesn’t care if it’s accidental. It doesn’t even care if it’s your fault. From Rule 80:
Players must be in control and responsible for their stick.
However, a player is permitted accidental contact on an opponent if the act is committed as a normal windup or follow through of a shooting motion, or accidental contact on the opposing center who is bent over during the course of a face-off. A wild swing at a bouncing puck would not be considered a normal windup or follow through and any contact to an opponent above the height of the shoulders shall be penalized accordingly.
(You can talk to Tampa’s Jake Guentzel about that last sentence.)
The Habs killed off the extra penalty to Guhle.
The Montreal Canadiens went on to defeat the Tampa Bay Lightning 4-3 in overtime to go up 1-0 in their best-of-seven opening round series in the Stanley Cup Playoffs. Referees for the game were Francois St. Laurent (#8) and Jake Brenk (#26), with Shandor Alphonso (#52) and Julien Fournier (#56) working the lines.