The incident occurred just moments after Connor McDavid's opening goal in the first period of Game 3 when Kane hit Kadri, sending him face-first into the boards. Kane was assessed a five-minute major penalty for boarding on the play but was not ejected.
"As they approach the corner, Kadri moves in front of Kane in order to establish body position between Kane and the puck. In response, and before either player can touch the puck, Kane raises his stick and delivers a shove to the back of Kadri, driving him into the boards with force and causing an injury. This is boarding," said the NHL's department of player safety in a video.
"It is important to note that this is not a scenario in which Kadri puts himself in a vulnerable position immediately prior to the hit in a way that turns a legal check into an illegal one.
"While we acknowledge that Kadri positions himself in front of Kane in order to shield the puck, this action is not a sudden or sharp movement that changes the nature of Kane's hit in a way that he cannot control. And while we acknowledge Kane's argument that Kadri loses his footing as he approaches the boards, we believe that this is a direct result of the shove and is not an unavoidable occurrence that causes an unfortunate accident."
The department of player safety went on to reference Kane's history of three suspensions and two fines over the course of his 812-game career.
Kadri did not return for the rest of the game, and though his injury has not been disclosed, it's suspected to be a right thumb injury, according to Sportsnet's Ken Wiebe.
Avalanche head coach Jared Bednar later said Kadri would not be playing again anytime soon.
"He's out — he'll be out for the series at least, if not longer. The hit is the most dangerous hit in hockey," he said.
Kane explained his view of what happened post-game:
“I was just coming in on the back-check. Puck went wide, kind of dribbled into the corner. I know he likes to reverse hit. I was just trying to get up on him, that’s really all I did,” said Kane. “Unfortunately he went into the boards awkwardly and hurt his hand.”