At 8:59 of the first period in the Canadiens/Rangers game, New York requested a Coach's Challenge to review whether Montreal's Max Pacioretty interfered with goaltender Henrik Lundqvist prior to Shea Weber's goal.
The Referee determined that Pacioretty prevented Lundqvist from doing his job in his crease, in accordance with Rule 78.7 which states in part: "The standard for overturning the call in the event of a 'GOAL' call on the ice is that the Referee ... determines that the goal should have been disallowed due to 'Interference on the Goalkeeper,' as described in Rules 69.1, 69.3 and 69.4."
Rule 69.1 states that goals should be disallowed if "an attacking player, either by his positioning or by contact, impairs the goalkeeper's ability to move freely within his crease or defend his goal."
Therefore the original call is overturned - no goal Montreal Canadiens.
Since the Coach's Challenge resulted in the original call being overturned, the New York Rangers retain their time-out.
Rule 78.7: Coach's Challenge
A team may only request a Coach's Challenge to review the following scenarios:
1. "Off-Side" Play Leading to a Goal
A play that results in a "GOAL" call on the ice where the defending team asserts that the play should have been stopped by reason of an "Off-side" infraction by the attacking team.
New for 2017-18: If the result of the challenge is that the play was "On-side", the goal shall count and the team that issued the challenge shall be assessed a minor penalty for delaying the game.
2. Scoring Plays Involving Potential "Interference on the Goalkeeper"
A play that results in a "GOAL" call on the ice where the defending team asserts that the goal should have been disallowed due to "Interference on the Goalkeeper," as described in Rules 69.1, 69.3 and 69.4; or
A play that results in a "NO GOAL" call on the ice despite the puck having entered the net, where the on-ice Officials have determined that the attacking team was guilty of "Interference on the Goalkeeper" but where the attacking team asserts: (i) there was no actual contact of any kind initiated by an attacking Player with the goalkeeper; or (ii) the attacking Player was pushed, shoved, or fouled by a defending Player causing the attacking Player to come into contact with the goalkeeper; or (iii) the attacking Player's positioning within the goal crease did not impair the goalkeeper's ability to defend his goal and, in fact, had no discernible impact on the play.
Updated for 2017-18: A team may only request a Coach's Challenge for Interference on the Goalkeeper if they have their time-out available and the Coach's Challenge must be effectively initiated prior to the resumption of play. If the Coach's Challenge does not result in the original call on the ice being overturned, the team exercising such challenge will forfeit its time-out. If the Coach's Challenge does result in the call on the ice being overturned, the team successfully exercising such challenge will retain its time-out.