GIF: Subban slash on Stone, potentially ending Subban’s night pic.twitter.com/Ak6pb34wiF— Stephanie Vail (@myregularface) April 16, 2015
61.3 Major Penalty - A major penalty, at the discretion of the Referee based on the severity of the contact, shall be imposed on a player who slashes an opponent. When injury occurs, a major penalty must be assessed under this rule (see 61.5).
61.4 Match Penalty – The Referee, at his discretion, may assess a match penalty if, in his judgment, the player attempted to or deliberately injured his opponent by slashing.
61.5 Game Misconduct Penalty – Whenever a major penalty is assessed for slashing, a game misconduct penalty must also be imposed.
It may have been automatic on the basis of Stone appearing to be injured (61.3/61.5), or it may have been at the discretion of the referees on the basis of the severity (61.3/61.4).
Either way, Subban was removed from the game. Kyle Turris also took a two minute roughing penalty on the ensuing scrum, but during the three minutes left on Subban's major the Senators scored twice (yay!) and the Canadiens scored once (boo!).
Stone returned to the game after a few minutes, but went to the dressing room again in the third.
Stone clearly not right, went back to the room— Pierre LeBrun (@Real_ESPNLeBrun) April 16, 2015